Beispiel #1
0
func simplifyNotExpr(n *parser.NotExpr) (parser.TypedExpr, bool) {
	switch t := n.Expr.(type) {
	case *parser.ComparisonExpr:
		op := t.Operator
		switch op {
		case parser.EQ:
			op = parser.NE
		case parser.NE:
			op = parser.EQ
		case parser.GT:
			op = parser.LE
		case parser.GE:
			op = parser.LT
		case parser.LT:
			op = parser.GE
		case parser.LE:
			op = parser.GT
		case parser.In:
			op = parser.NotIn
		case parser.NotIn:
			op = parser.In
		case parser.Like:
			op = parser.NotLike
		case parser.NotLike:
			op = parser.Like
		case parser.SimilarTo:
			op = parser.NotSimilarTo
		case parser.NotSimilarTo:
			op = parser.SimilarTo
		default:
			return parser.MakeDBool(true), false
		}
		return simplifyExpr(parser.NewTypedComparisonExpr(
			op,
			t.TypedLeft(),
			t.TypedRight(),
		))

	case *parser.AndExpr:
		// De Morgan's Law: NOT (a AND b) -> (NOT a) OR (NOT b)
		return simplifyExpr(parser.NewTypedOrExpr(
			parser.NewTypedNotExpr(t.TypedLeft()),
			parser.NewTypedNotExpr(t.TypedRight()),
		))

	case *parser.OrExpr:
		// De Morgan's Law: NOT (a OR b) -> (NOT a) AND (NOT b)
		return simplifyExpr(parser.NewTypedAndExpr(
			parser.NewTypedNotExpr(t.TypedLeft()),
			parser.NewTypedNotExpr(t.TypedRight()),
		))
	}
	return parser.MakeDBool(true), false
}
Beispiel #2
0
// ShowIndex returns all the indexes for a table.
// Privileges: Any privilege on table.
//   Notes: postgres does not have a SHOW INDEXES statement.
//          mysql requires some privilege for any column.
func (p *planner) ShowIndex(n *parser.ShowIndex) (planNode, error) {
	tn, err := n.Table.NormalizeWithDatabaseName(p.session.Database)
	if err != nil {
		return nil, err
	}

	desc, err := p.mustGetTableDesc(tn)
	if err != nil {
		return nil, err
	}
	if err := p.anyPrivilege(desc); err != nil {
		return nil, err
	}

	v := &valuesNode{
		columns: []ResultColumn{
			{Name: "Table", Typ: parser.TypeString},
			{Name: "Name", Typ: parser.TypeString},
			{Name: "Unique", Typ: parser.TypeBool},
			{Name: "Seq", Typ: parser.TypeInt},
			{Name: "Column", Typ: parser.TypeString},
			{Name: "Direction", Typ: parser.TypeString},
			{Name: "Storing", Typ: parser.TypeBool},
		},
	}

	appendRow := func(index sqlbase.IndexDescriptor, colName string, sequence int,
		direction string, isStored bool) {
		v.rows = append(v.rows, []parser.Datum{
			parser.NewDString(tn.Table()),
			parser.NewDString(index.Name),
			parser.MakeDBool(parser.DBool(index.Unique)),
			parser.NewDInt(parser.DInt(sequence)),
			parser.NewDString(colName),
			parser.NewDString(direction),
			parser.MakeDBool(parser.DBool(isStored)),
		})
	}

	for _, index := range append([]sqlbase.IndexDescriptor{desc.PrimaryIndex}, desc.Indexes...) {
		sequence := 1
		for i, col := range index.ColumnNames {
			appendRow(index, col, sequence, index.ColumnDirections[i].String(), false)
			sequence++
		}
		for _, col := range index.StoreColumnNames {
			appendRow(index, col, sequence, "N/A", true)
			sequence++
		}
	}
	return v, nil
}
Beispiel #3
0
// ShowColumns of a table.
// Privileges: None.
//   Notes: postgres does not have a SHOW COLUMNS statement.
//          mysql only returns columns you have privileges on.
func (p *planner) ShowColumns(n *parser.ShowColumns) (planNode, error) {
	desc, err := p.getTableDesc(n.Table)
	if err != nil {
		return nil, err
	}
	if desc == nil {
		return nil, sqlbase.NewUndefinedTableError(n.Table.String())
	}
	v := &valuesNode{
		columns: []ResultColumn{
			{Name: "Field", Typ: parser.TypeString},
			{Name: "Type", Typ: parser.TypeString},
			{Name: "Null", Typ: parser.TypeBool},
			{Name: "Default", Typ: parser.TypeString},
		},
	}
	for i, col := range desc.Columns {
		defaultExpr := parser.Datum(parser.DNull)
		if e := desc.Columns[i].DefaultExpr; e != nil {
			defaultExpr = parser.NewDString(*e)
		}
		v.rows = append(v.rows, []parser.Datum{
			parser.NewDString(desc.Columns[i].Name),
			parser.NewDString(col.Type.SQLString()),
			parser.MakeDBool(parser.DBool(desc.Columns[i].Nullable)),
			defaultExpr,
		})
	}
	return v, nil
}
Beispiel #4
0
// DecodeTableValue decodes a value encoded by EncodeTableValue.
func DecodeTableValue(a *DatumAlloc, valType parser.Datum, b []byte) (parser.Datum, []byte, error) {
	// TODO(dan): Merge this and DecodeTableKey.
	if len(b) == 0 {
		return nil, nil, util.Errorf("empty slice")
	}
	if roachpb.ValueType(b[0]) == roachpb.ValueType_NULL {
		return parser.DNull, b[1:], nil
	}
	var err error
	switch valType.(type) {
	case *parser.DBool:
		var i int64
		b, i, err = roachpb.DecodeIntValue(b)
		// No need to chunk allocate DBool as MakeDBool returns either
		// parser.DBoolTrue or parser.DBoolFalse.
		return parser.MakeDBool(parser.DBool(i != 0)), b, err
	case *parser.DInt:
		var i int64
		b, i, err = roachpb.DecodeIntValue(b)
		return a.NewDInt(parser.DInt(i)), b, err
	case *parser.DFloat:
		var f float64
		b, f, err = roachpb.DecodeFloatValue(b)
		return a.NewDFloat(parser.DFloat(f)), b, err
	case *parser.DDecimal:
		var d *inf.Dec
		b, d, err = roachpb.DecodeDecimalValue(b)
		dd := a.NewDDecimal(parser.DDecimal{})
		dd.Set(d)
		return dd, b, err
	case *parser.DString:
		var data []byte
		b, data, err = roachpb.DecodeBytesValue(b)
		return a.NewDString(parser.DString(data)), b, err
	case *parser.DBytes:
		var data []byte
		b, data, err = roachpb.DecodeBytesValue(b)
		return a.NewDBytes(parser.DBytes(data)), b, err
	case *parser.DDate:
		var i int64
		b, i, err = roachpb.DecodeIntValue(b)
		return a.NewDDate(parser.DDate(i)), b, err
	case *parser.DTimestamp:
		var t time.Time
		b, t, err = roachpb.DecodeTimeValue(b)
		return a.NewDTimestamp(parser.DTimestamp{Time: t}), b, err
	case *parser.DTimestampTZ:
		var t time.Time
		b, t, err = roachpb.DecodeTimeValue(b)
		return a.NewDTimestampTZ(parser.DTimestampTZ{Time: t}), b, err
	case *parser.DInterval:
		var d duration.Duration
		b, d, err = roachpb.DecodeDurationValue(b)
		return a.NewDInterval(parser.DInterval{Duration: d}), b, err
	default:
		return nil, nil, util.Errorf("TODO(pmattis): decoded index value: %s", valType.Type())
	}
}
Beispiel #5
0
// DecodeTableValue decodes a value encoded by EncodeTableValue.
func DecodeTableValue(a *DatumAlloc, valType parser.Datum, b []byte) (parser.Datum, []byte, error) {
	_, dataOffset, _, typ, err := encoding.DecodeValueTag(b)
	if err != nil {
		return nil, b, err
	}
	if typ == encoding.Null {
		return parser.DNull, b[dataOffset:], nil
	}
	switch valType.(type) {
	case *parser.DBool:
		var x bool
		b, x, err = encoding.DecodeBoolValue(b)
		// No need to chunk allocate DBool as MakeDBool returns either
		// parser.DBoolTrue or parser.DBoolFalse.
		return parser.MakeDBool(parser.DBool(x)), b, err
	case *parser.DInt:
		var i int64
		b, i, err = encoding.DecodeIntValue(b)
		return a.NewDInt(parser.DInt(i)), b, err
	case *parser.DFloat:
		var f float64
		b, f, err = encoding.DecodeFloatValue(b)
		return a.NewDFloat(parser.DFloat(f)), b, err
	case *parser.DDecimal:
		var d *inf.Dec
		b, d, err = encoding.DecodeDecimalValue(b)
		dd := a.NewDDecimal(parser.DDecimal{})
		dd.Set(d)
		return dd, b, err
	case *parser.DString:
		var data []byte
		b, data, err = encoding.DecodeBytesValue(b)
		return a.NewDString(parser.DString(data)), b, err
	case *parser.DBytes:
		var data []byte
		b, data, err = encoding.DecodeBytesValue(b)
		return a.NewDBytes(parser.DBytes(data)), b, err
	case *parser.DDate:
		var i int64
		b, i, err = encoding.DecodeIntValue(b)
		return a.NewDDate(parser.DDate(i)), b, err
	case *parser.DTimestamp:
		var t time.Time
		b, t, err = encoding.DecodeTimeValue(b)
		return a.NewDTimestamp(parser.DTimestamp{Time: t}), b, err
	case *parser.DTimestampTZ:
		var t time.Time
		b, t, err = encoding.DecodeTimeValue(b)
		return a.NewDTimestampTZ(parser.DTimestampTZ{Time: t}), b, err
	case *parser.DInterval:
		var d duration.Duration
		b, d, err = encoding.DecodeDurationValue(b)
		return a.NewDInterval(parser.DInterval{Duration: d}), b, err
	default:
		return nil, nil, errors.Errorf("TODO(pmattis): decoded index value: %s", valType.Type())
	}
}
Beispiel #6
0
// golangFillQueryArguments populates the placeholder map with
// types and values from an array of Go values.
// TODO: This does not support arguments of the SQL 'Date' type, as there is not
// an equivalent type in Go's standard library. It's not currently needed by any
// of our internal tables.
func golangFillQueryArguments(pinfo *parser.PlaceholderInfo, args []interface{}) {
	pinfo.Clear()

	for i, arg := range args {
		k := fmt.Sprint(i + 1)
		if arg == nil {
			pinfo.SetValue(k, parser.DNull)
			continue
		}

		// A type switch to handle a few explicit types with special semantics:
		// - Datums are passed along as is.
		// - Time datatypes get special representation in the database.
		var d parser.Datum
		switch t := arg.(type) {
		case parser.Datum:
			d = t
		case time.Time:
			d = parser.MakeDTimestamp(t, time.Microsecond)
		case time.Duration:
			d = &parser.DInterval{Duration: duration.Duration{Nanos: t.Nanoseconds()}}
		case *inf.Dec:
			dd := &parser.DDecimal{}
			dd.Set(t)
			d = dd
		}
		if d == nil {
			// Handle all types which have an underlying type that can be stored in the
			// database.
			// Note: if this reflection becomes a performance concern in the future,
			// commonly used types could be added explicitly into the type switch above
			// for a performance gain.
			val := reflect.ValueOf(arg)
			switch val.Kind() {
			case reflect.Bool:
				d = parser.MakeDBool(parser.DBool(val.Bool()))
			case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
				d = parser.NewDInt(parser.DInt(val.Int()))
			case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
				d = parser.NewDInt(parser.DInt(val.Uint()))
			case reflect.Float32, reflect.Float64:
				d = parser.NewDFloat(parser.DFloat(val.Float()))
			case reflect.String:
				d = parser.NewDString(val.String())
			case reflect.Slice:
				// Handle byte slices.
				if val.Type().Elem().Kind() == reflect.Uint8 {
					d = parser.NewDBytes(parser.DBytes(val.Bytes()))
				}
			}
			if d == nil {
				panic(fmt.Sprintf("unexpected type %T", arg))
			}
		}
		pinfo.SetValue(k, d)
	}
}
Beispiel #7
0
// Arg implements the parser.Args interface.
// TODO: This does not support arguments of the SQL 'Date' type, as there is not
// an equivalent type in Go's standard library. It's not currently needed by any
// of our internal tables.
func (gp golangParameters) Arg(name string) (parser.Datum, bool) {
	i, err := processPositionalArgument(name)
	if err != nil {
		return nil, false
	}
	if i < 1 || int(i) > len(gp) {
		return nil, false
	}
	arg := gp[i-1]
	if arg == nil {
		return parser.DNull, true
	}

	// A type switch to handle a few explicit types with special semantics.
	switch t := arg.(type) {
	// Datums are passed along as is.
	case parser.Datum:
		return t, true
	// Time datatypes get special representation in the database.
	case time.Time:
		return parser.MakeDTimestamp(t, time.Microsecond), true
	case time.Duration:
		return &parser.DInterval{Duration: duration.Duration{Nanos: t.Nanoseconds()}}, true
	case *inf.Dec:
		dd := &parser.DDecimal{}
		dd.Set(t)
		return dd, true
	}

	// Handle all types which have an underlying type that can be stored in the
	// database.
	// Note: if this reflection becomes a performance concern in the future,
	// commonly used types could be added explicitly into the type switch above
	// for a performance gain.
	val := reflect.ValueOf(arg)
	switch val.Kind() {
	case reflect.Bool:
		return parser.MakeDBool(parser.DBool(val.Bool())), true
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return parser.NewDInt(parser.DInt(val.Int())), true
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		return parser.NewDInt(parser.DInt(val.Uint())), true
	case reflect.Float32, reflect.Float64:
		return parser.NewDFloat(parser.DFloat(val.Float())), true
	case reflect.String:
		return parser.NewDString(val.String()), true
	case reflect.Slice:
		// Handle byte slices.
		if val.Type().Elem().Kind() == reflect.Uint8 {
			return parser.NewDBytes(parser.DBytes(val.Bytes())), true
		}
	}

	panic(fmt.Sprintf("unexpected type %T", arg))
}
Beispiel #8
0
func simplifyAndExpr(n *parser.AndExpr) (parser.TypedExpr, bool) {
	// a AND b AND c AND d -> [a, b, c, d]
	equivalent := true
	exprs := splitAndExpr(n, nil)
	for i := range exprs {
		var equiv bool
		exprs[i], equiv = simplifyExpr(exprs[i])
		if !equiv {
			equivalent = false
		}
		if isKnownFalseOrNull(exprs[i]) {
			return parser.MakeDBool(false), equivalent
		}
	}
	// Simplifying exprs might have transformed one of the elements into an AND
	// expression.
	texprs, exprs := exprs, nil
	for _, e := range texprs {
		exprs = splitAndExpr(e, exprs)
	}

	// Loop over the expressions looking for simplifications.
	//
	// TODO(pmattis): This is O(n^2) in the number of expressions. Could be
	// optimized by sorting the expressions based on the variables they contain.
outer:
	for i := len(exprs) - 1; i >= 0; i-- {
		for j := i - 1; j >= 0; j-- {
			var equiv bool
			exprs[j], exprs[i], equiv = simplifyOneAndExpr(exprs[j], exprs[i])
			if !equiv {
				equivalent = false
			}
			if isKnownFalseOrNull(exprs[j]) {
				return exprs[j], equivalent
			}
			if isKnownTrue(exprs[i]) {
				exprs[i] = nil
			}
			if exprs[i] == nil {
				// We found a simplification. Strip off the expression that is now nil
				// and continue the outer loop.
				n := len(exprs) - 1
				exprs[i] = exprs[n]
				exprs = exprs[:n]
				continue outer
			}
		}
	}

	// Reform the AND expressions.
	return joinAndExprs(exprs), equivalent
}
Beispiel #9
0
// simplifyExpr transforms an expression such that it contains only expressions
// involving qvalues that can be used for index selection. If an expression is
// encountered that cannot be used for index selection (e.g. "func(val)") that
// part of the expression tree is considered to evaluate to true, possibly
// rendering the entire expression as true. Additionally, various
// normalizations are performed on comparison expressions. For example:
//
//   (a < 1 AND a < 2)  -> (a < 1)
//   (a < 1 AND a > 2)  -> false
//   (a > 1 OR a < 2)   -> true
//   (a > 1 OR func(b)) -> true
//
// Note that simplification is not normalization. Normalization as performed by
// parser.NormalizeExpr returns an expression that is equivalent to the
// original. Simplification can return an expression with parts of the
// expression tree stripped out.
//
// Returns false for equivalent if the resulting expression is not equivalent
// to the original. This occurs for expressions which are currently not handled
// by simplification.
func simplifyExpr(e parser.TypedExpr) (simplified parser.TypedExpr, equivalent bool) {
	switch t := e.(type) {
	case *parser.NotExpr:
		return simplifyNotExpr(t)
	case *parser.AndExpr:
		return simplifyAndExpr(t)
	case *parser.OrExpr:
		return simplifyOrExpr(t)
	case *parser.ComparisonExpr:
		return simplifyComparisonExpr(t)
	case *qvalue, *parser.IndexedVar, *parser.DBool:
		return e, true
	}
	// We don't know how to simplify expressions that fall through to here, so
	// consider this part of the expression true.
	return parser.MakeDBool(true), false
}
Beispiel #10
0
// RandDatum generates a random Datum of the given type.
// If null is true, the datum can be DNull.
func RandDatum(rng *rand.Rand, typ ColumnType_Kind, null bool) parser.Datum {
	if null && rng.Intn(10) == 0 {
		return parser.DNull
	}
	switch typ {
	case ColumnType_BOOL:
		return parser.MakeDBool(rng.Intn(2) == 1)
	case ColumnType_INT:
		return parser.NewDInt(parser.DInt(rng.Int63()))
	case ColumnType_FLOAT:
		return parser.NewDFloat(parser.DFloat(rng.NormFloat64()))
	case ColumnType_DECIMAL:
		d := &parser.DDecimal{}
		d.Dec.SetScale(inf.Scale(rng.Intn(40) - 20))
		d.Dec.SetUnscaled(rng.Int63())
		return d
	case ColumnType_DATE:
		return parser.NewDDate(parser.DDate(rng.Intn(10000)))
	case ColumnType_TIMESTAMP:
		return &parser.DTimestamp{Time: time.Unix(rng.Int63n(1000000), rng.Int63n(1000000))}
	case ColumnType_INTERVAL:
		return &parser.DInterval{Duration: duration.Duration{Months: rng.Int63n(1000),
			Days:  rng.Int63n(1000),
			Nanos: rng.Int63n(1000000),
		}}
	case ColumnType_STRING:
		// Generate a random ASCII string.
		p := make([]byte, rng.Intn(10))
		for i := range p {
			p[i] = byte(1 + rng.Intn(127))
		}
		return parser.NewDString(string(p))
	case ColumnType_BYTES:
		p := make([]byte, rng.Intn(10))
		_, _ = rng.Read(p)
		return parser.NewDBytes(parser.DBytes(p))
	case ColumnType_TIMESTAMPTZ:
		return &parser.DTimestampTZ{Time: time.Unix(rng.Int63n(1000000), rng.Int63n(1000000))}
	default:
		panic(fmt.Sprintf("invalid type %s", typ))
	}
}
Beispiel #11
0
// ShowColumns of a table.
// Privileges: Any privilege on table.
//   Notes: postgres does not have a SHOW COLUMNS statement.
//          mysql only returns columns you have privileges on.
func (p *planner) ShowColumns(n *parser.ShowColumns) (planNode, error) {
	tn, err := n.Table.NormalizeWithDatabaseName(p.session.Database)
	if err != nil {
		return nil, err
	}

	desc, err := p.mustGetTableDesc(tn)
	if err != nil {
		return nil, err
	}
	if err := p.anyPrivilege(desc); err != nil {
		return nil, err
	}

	v := &valuesNode{
		columns: []ResultColumn{
			{Name: "Field", Typ: parser.TypeString},
			{Name: "Type", Typ: parser.TypeString},
			{Name: "Null", Typ: parser.TypeBool},
			{Name: "Default", Typ: parser.TypeString},
		},
	}

	for i, col := range desc.Columns {
		defaultExpr := parser.DNull
		if e := desc.Columns[i].DefaultExpr; e != nil {
			defaultExpr = parser.NewDString(*e)
		}
		v.rows = append(v.rows, []parser.Datum{
			parser.NewDString(desc.Columns[i].Name),
			parser.NewDString(col.Type.SQLString()),
			parser.MakeDBool(parser.DBool(desc.Columns[i].Nullable)),
			defaultExpr,
		})
	}
	return v, nil
}
Beispiel #12
0
func makePrefixRange(prefix parser.DString, datum parser.TypedExpr, complete bool) parser.TypedExpr {
	if complete {
		return parser.NewTypedComparisonExpr(
			parser.EQ,
			datum,
			&prefix,
		)
	}
	if len(prefix) == 0 {
		return parser.MakeDBool(true)
	}
	return parser.NewTypedAndExpr(
		parser.NewTypedComparisonExpr(
			parser.GE,
			datum,
			&prefix,
		),
		parser.NewTypedComparisonExpr(
			parser.LT,
			datum,
			parser.NewDString(string(roachpb.Key(prefix).PrefixEnd())),
		),
	)
}
Beispiel #13
0
// decodeOidDatum decodes bytes with specified Oid and format code into
// a datum.
func decodeOidDatum(id oid.Oid, code formatCode, b []byte) (parser.Datum, error) {
	var d parser.Datum
	switch id {
	case oid.T_bool:
		switch code {
		case formatText:
			v, err := strconv.ParseBool(string(b))
			if err != nil {
				return d, err
			}
			d = parser.MakeDBool(parser.DBool(v))
		case formatBinary:
			switch b[0] {
			case 0:
				d = parser.MakeDBool(false)
			case 1:
				d = parser.MakeDBool(true)
			default:
				return d, util.Errorf("unsupported binary bool: %q", b)
			}
		default:
			return d, util.Errorf("unsupported bool format code: %s", code)
		}
	case oid.T_int2:
		switch code {
		case formatText:
			i, err := strconv.ParseInt(string(b), 10, 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		case formatBinary:
			var i int16
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &i)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		default:
			return d, util.Errorf("unsupported int2 format code: %s", code)
		}
	case oid.T_int4:
		switch code {
		case formatText:
			i, err := strconv.ParseInt(string(b), 10, 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		case formatBinary:
			var i int32
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &i)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		default:
			return d, util.Errorf("unsupported int4 format code: %s", code)
		}
	case oid.T_int8:
		switch code {
		case formatText:
			i, err := strconv.ParseInt(string(b), 10, 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		case formatBinary:
			var i int64
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &i)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		default:
			return d, util.Errorf("unsupported int8 format code: %s", code)
		}
	case oid.T_float4:
		switch code {
		case formatText:
			f, err := strconv.ParseFloat(string(b), 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDFloat(parser.DFloat(f))
		case formatBinary:
			var f float32
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &f)
			if err != nil {
				return d, err
			}
			d = parser.NewDFloat(parser.DFloat(f))
		default:
			return d, util.Errorf("unsupported float4 format code: %s", code)
		}
	case oid.T_float8:
		switch code {
		case formatText:
			f, err := strconv.ParseFloat(string(b), 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDFloat(parser.DFloat(f))
		case formatBinary:
			var f float64
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &f)
			if err != nil {
				return d, err
			}
			d = parser.NewDFloat(parser.DFloat(f))
		default:
			return d, util.Errorf("unsupported float8 format code: %s", code)
		}
	case oid.T_numeric:
		switch code {
		case formatText:
			dd := &parser.DDecimal{}
			if _, ok := dd.SetString(string(b)); !ok {
				return nil, util.Errorf("could not parse string %q as decimal", b)
			}
			d = dd
		case formatBinary:
			r := bytes.NewReader(b)

			alloc := struct {
				pgNum pgNumeric
				i16   int16

				dd parser.DDecimal
			}{}

			for _, ptr := range []interface{}{
				&alloc.pgNum.ndigits,
				&alloc.pgNum.weight,
				&alloc.pgNum.sign,
				&alloc.pgNum.dscale,
			} {
				if err := binary.Read(r, binary.BigEndian, ptr); err != nil {
					return d, err
				}
			}

			decDigits := make([]byte, 0, alloc.pgNum.ndigits*pgDecDigits)
			for i := int16(0); i < alloc.pgNum.ndigits-1; i++ {
				if err := binary.Read(r, binary.BigEndian, &alloc.i16); err != nil {
					return d, err
				}
				decDigits = strconv.AppendUint(decDigits, uint64(alloc.i16), 10)
			}

			// The last digit may contain padding, which we need to deal with.
			if err := binary.Read(r, binary.BigEndian, &alloc.i16); err != nil {
				return d, err
			}
			dscale := (alloc.pgNum.ndigits - 1 - alloc.pgNum.weight) * pgDecDigits
			if overScale := dscale - alloc.pgNum.dscale; overScale > 0 {
				dscale -= overScale
				for i := int16(0); i < overScale; i++ {
					alloc.i16 /= 10
				}
			}
			decDigits = strconv.AppendUint(decDigits, uint64(alloc.i16), 10)
			alloc.dd.UnscaledBig().SetString(string(decDigits), 10)
			alloc.dd.SetScale(inf.Scale(dscale))

			switch alloc.pgNum.sign {
			case pgNumericPos:
			case pgNumericNeg:
				alloc.dd.Neg(&alloc.dd.Dec)
			default:
				return d, util.Errorf("unsupported numeric sign: %s", alloc.pgNum.sign)
			}

			d = &alloc.dd
		default:
			return d, util.Errorf("unsupported numeric format code: %s", code)
		}
	case oid.T_text, oid.T_varchar:
		switch code {
		case formatText, formatBinary:
			d = parser.NewDString(string(b))
		default:
			return d, util.Errorf("unsupported text format code: %s", code)
		}
	case oid.T_bytea:
		switch code {
		case formatText:
			// http://www.postgresql.org/docs/current/static/datatype-binary.html#AEN5667
			// Code cribbed from github.com/lib/pq.

			// We only support hex encoding.
			if len(b) >= 2 && bytes.Equal(b[:2], []byte("\\x")) {
				b = b[2:] // trim off leading "\\x"
				result := make([]byte, hex.DecodedLen(len(b)))
				_, err := hex.Decode(result, b)
				if err != nil {
					return d, err
				}
				d = parser.NewDBytes(parser.DBytes(result))
			} else {
				return d, util.Errorf("unsupported bytea encoding: %q", b)
			}
		case formatBinary:
			d = parser.NewDBytes(parser.DBytes(b))
		default:
			return d, util.Errorf("unsupported bytea format code: %s", code)
		}
	case oid.T_timestamp, oid.T_timestamptz:
		switch code {
		case formatText:
			ts, err := parseTs(string(b))
			if err != nil {
				return d, util.Errorf("could not parse string %q as timestamp", b)
			}
			d = parser.MakeDTimestamp(ts, time.Microsecond)
		default:
			return d, util.Errorf("unsupported timestamp format code: %s", code)
		}
	case oid.T_date:
		switch code {
		case formatText:
			ts, err := parseTs(string(b))
			if err != nil {
				return d, util.Errorf("could not parse string %q as date", b)
			}
			daysSinceEpoch := ts.Unix() / secondsInDay
			d = parser.NewDDate(parser.DDate(daysSinceEpoch))
		default:
			return d, util.Errorf("unsupported date format code: %s", code)
		}
	default:
		return d, util.Errorf("unsupported OID: %v", id)
	}
	return d, nil
}
Beispiel #14
0
// UnmarshalColumnValue decodes the value from a key-value pair using the type
// expected by the column. An error is returned if the value's type does not
// match the column's type.
func UnmarshalColumnValue(
	a *DatumAlloc, kind ColumnType_Kind, value *roachpb.Value,
) (parser.Datum, error) {
	if value == nil {
		return parser.DNull, nil
	}

	switch kind {
	case ColumnType_BOOL:
		v, err := value.GetInt()
		if err != nil {
			return nil, err
		}
		return parser.MakeDBool(parser.DBool(v != 0)), nil
	case ColumnType_INT:
		v, err := value.GetInt()
		if err != nil {
			return nil, err
		}
		return a.NewDInt(parser.DInt(v)), nil
	case ColumnType_FLOAT:
		v, err := value.GetFloat()
		if err != nil {
			return nil, err
		}
		return a.NewDFloat(parser.DFloat(v)), nil
	case ColumnType_DECIMAL:
		v, err := value.GetDecimal()
		if err != nil {
			return nil, err
		}
		dd := a.NewDDecimal(parser.DDecimal{})
		dd.Set(v)
		return dd, nil
	case ColumnType_STRING:
		v, err := value.GetBytes()
		if err != nil {
			return nil, err
		}
		return a.NewDString(parser.DString(v)), nil
	case ColumnType_BYTES:
		v, err := value.GetBytes()
		if err != nil {
			return nil, err
		}
		return a.NewDBytes(parser.DBytes(v)), nil
	case ColumnType_DATE:
		v, err := value.GetInt()
		if err != nil {
			return nil, err
		}
		return a.NewDDate(parser.DDate(v)), nil
	case ColumnType_TIMESTAMP:
		v, err := value.GetTime()
		if err != nil {
			return nil, err
		}
		return a.NewDTimestamp(parser.DTimestamp{Time: v}), nil
	case ColumnType_TIMESTAMPTZ:
		v, err := value.GetTime()
		if err != nil {
			return nil, err
		}
		return a.NewDTimestampTZ(parser.DTimestampTZ{Time: v}), nil
	case ColumnType_INTERVAL:
		d, err := value.GetDuration()
		if err != nil {
			return nil, err
		}
		return a.NewDInterval(parser.DInterval{Duration: d}), nil
	default:
		return nil, util.Errorf("unsupported column type: %s", kind)
	}
}
Beispiel #15
0
// DecodeTableKey decodes a table key/value.
func DecodeTableKey(
	a *DatumAlloc, valType parser.Datum, key []byte, dir encoding.Direction,
) (parser.Datum, []byte, error) {
	if (dir != encoding.Ascending) && (dir != encoding.Descending) {
		return nil, nil, util.Errorf("invalid direction: %d", dir)
	}
	var isNull bool
	if key, isNull = encoding.DecodeIfNull(key); isNull {
		return parser.DNull, key, nil
	}
	var rkey []byte
	var err error
	switch valType.(type) {
	case *parser.DBool:
		var i int64
		if dir == encoding.Ascending {
			rkey, i, err = encoding.DecodeVarintAscending(key)
		} else {
			rkey, i, err = encoding.DecodeVarintDescending(key)
		}
		// No need to chunk allocate DBool as MakeDBool returns either
		// parser.DBoolTrue or parser.DBoolFalse.
		return parser.MakeDBool(parser.DBool(i != 0)), rkey, err
	case *parser.DInt:
		var i int64
		if dir == encoding.Ascending {
			rkey, i, err = encoding.DecodeVarintAscending(key)
		} else {
			rkey, i, err = encoding.DecodeVarintDescending(key)
		}
		return a.NewDInt(parser.DInt(i)), rkey, err
	case *parser.DFloat:
		var f float64
		if dir == encoding.Ascending {
			rkey, f, err = encoding.DecodeFloatAscending(key)
		} else {
			rkey, f, err = encoding.DecodeFloatDescending(key)
		}
		return a.NewDFloat(parser.DFloat(f)), rkey, err
	case *parser.DDecimal:
		var d *inf.Dec
		if dir == encoding.Ascending {
			rkey, d, err = encoding.DecodeDecimalAscending(key, nil)
		} else {
			rkey, d, err = encoding.DecodeDecimalDescending(key, nil)
		}
		dd := a.NewDDecimal(parser.DDecimal{})
		dd.Set(d)
		return dd, rkey, err
	case *parser.DString:
		var r string
		if dir == encoding.Ascending {
			rkey, r, err = encoding.DecodeUnsafeStringAscending(key, nil)
		} else {
			rkey, r, err = encoding.DecodeUnsafeStringDescending(key, nil)
		}
		return a.NewDString(parser.DString(r)), rkey, err
	case *parser.DBytes:
		var r []byte
		if dir == encoding.Ascending {
			rkey, r, err = encoding.DecodeBytesAscending(key, nil)
		} else {
			rkey, r, err = encoding.DecodeBytesDescending(key, nil)
		}
		return a.NewDBytes(parser.DBytes(r)), rkey, err
	case *parser.DDate:
		var t int64
		if dir == encoding.Ascending {
			rkey, t, err = encoding.DecodeVarintAscending(key)
		} else {
			rkey, t, err = encoding.DecodeVarintDescending(key)
		}
		return a.NewDDate(parser.DDate(t)), rkey, err
	case *parser.DTimestamp:
		var t time.Time
		if dir == encoding.Ascending {
			rkey, t, err = encoding.DecodeTimeAscending(key)
		} else {
			rkey, t, err = encoding.DecodeTimeDescending(key)
		}
		return a.NewDTimestamp(parser.DTimestamp{Time: t}), rkey, err
	case *parser.DTimestampTZ:
		var t time.Time
		if dir == encoding.Ascending {
			rkey, t, err = encoding.DecodeTimeAscending(key)
		} else {
			rkey, t, err = encoding.DecodeTimeDescending(key)
		}
		return a.NewDTimestampTZ(parser.DTimestampTZ{Time: t}), rkey, err
	case *parser.DInterval:
		var d duration.Duration
		if dir == encoding.Ascending {
			rkey, d, err = encoding.DecodeDurationAscending(key)
		} else {
			rkey, d, err = encoding.DecodeDurationDescending(key)
		}
		return a.NewDInterval(parser.DInterval{Duration: d}), rkey, err
	default:
		return nil, nil, util.Errorf("TODO(pmattis): decoded index key: %s", valType.Type())
	}
}
Beispiel #16
0
// splitBoolExpr splits a boolean expression E into two boolean expressions RES and REM such that:
//
//  - RES only has variables known to the conversion function (it is "restricted" to a particular
//    set of variables)
//
//  - If weaker is true, for any setting of variables x:
//       E(x) = (RES(x) AND REM(x))
//    This implies RES(x) <= E(x), i.e. RES is "weaker"
//
//  - If weaker is false:
//       E(x) = (RES(x) OR REM(x))
//    This implies RES(x) => E(x), i.e. RES is "stronger"
func splitBoolExpr(expr parser.TypedExpr, conv varConvertFunc, weaker bool) (restricted, remainder parser.TypedExpr) {
	// If the expression only contains "restricted" vars, the split is trivial.
	if exprCheckVars(expr, conv) {
		// An "empty" filter is always true in the weaker (normal) case (where the filter is
		// equivalent to RES AND REM) and always false in the stronger (inverted) case (where the
		// filter is equivalent to RES OR REM).
		return exprConvertVars(expr, conv), parser.MakeDBool(parser.DBool(weaker))
	}

	switch t := expr.(type) {
	case *parser.AndExpr:
		if weaker {
			// In the weaker (normal) case, we have
			//   E = (leftRes AND leftRem) AND (rightRes AND rightRem)
			// We can just rearrange:
			//   E = (leftRes AND rightRes) AND (leftRem AND rightRem)
			leftRes, leftRem := splitBoolExpr(t.TypedLeft(), conv, weaker)
			rightRes, rightRem := splitBoolExpr(t.TypedRight(), conv, weaker)
			return makeAnd(leftRes, rightRes), makeAnd(leftRem, rightRem)
		}

		// In the stronger (inverted) case, we have
		//   E = (leftRes OR leftRem) AND (rightRes OR rightRem)
		// We can't do more than:
		//   E = (leftRes AND rightRes) OR E
		leftRes, _ := splitBoolExpr(t.TypedLeft(), conv, weaker)
		rightRes, _ := splitBoolExpr(t.TypedRight(), conv, weaker)
		return makeAnd(leftRes, rightRes), expr

	case *parser.OrExpr:
		if !weaker {
			// In the stronger (inverted) case, we have
			//   E = (leftRes OR leftRem) OR (rightRes AND rightRem)
			// We can just rearrange:
			//   E = (leftRes OR rightRes) OR (leftRem AND rightRem)
			leftRes, leftRem := splitBoolExpr(t.TypedLeft(), conv, weaker)
			rightRes, rightRem := splitBoolExpr(t.TypedRight(), conv, weaker)
			return makeOr(leftRes, rightRes), makeOr(leftRem, rightRem)
		}

		// In the weaker (normal) case, we have
		//   E = (leftRes AND leftRem) OR (rightRes AND rightRem)
		// We can't do more than:
		//   E = (leftRes OR rightRes) OR E
		leftRes, _ := splitBoolExpr(t.TypedLeft(), conv, weaker)
		rightRes, _ := splitBoolExpr(t.TypedRight(), conv, weaker)
		return makeOr(leftRes, rightRes), expr

	case *parser.ParenExpr:
		return splitBoolExpr(t.TypedInnerExpr(), conv, weaker)

	case *parser.NotExpr:
		exprRes, exprRem := splitBoolExpr(t.TypedInnerExpr(), conv, !weaker)
		return makeNot(exprRes), makeNot(exprRem)

	default:
		// We can't split off anything (we already handled the case when expr contains only
		// restricted vars above).
		// For why we return DBool(weaker), see the comment above on "empty" filters.
		return parser.MakeDBool(parser.DBool(weaker)), expr
	}
}
Beispiel #17
0
func (v *subqueryVisitor) VisitPre(expr parser.Expr) (recurse bool, newExpr parser.Expr) {
	if v.err != nil {
		return false, expr
	}
	v.path = append(v.path, expr)

	var exists *parser.ExistsExpr
	subquery, ok := expr.(*parser.Subquery)
	if !ok {
		exists, ok = expr.(*parser.ExistsExpr)
		if !ok {
			return true, expr
		}
		subquery, ok = exists.Subquery.(*parser.Subquery)
		if !ok {
			return true, expr
		}
	}

	// Calling makePlan() might recursively invoke expandSubqueries, so we need a
	// copy of the planner in order for there to have a separate subqueryVisitor.
	// TODO(nvanbenschoten) We should propagate a desired type here.
	// TODO(knz) the instantiation of the subquery's select node should be moved
	//     to the TypeCheck() method once the prepare and execute phase are separated
	//     for select nodes.
	planMaker := *v.planner
	plan, err := planMaker.makePlan(subquery.Select, nil, false)
	if err != nil {
		return false, expr
	}

	if v.evalCtx.PrepareOnly {
		return false, expr
	}

	if v.err = plan.Start(); v.err != nil {
		return false, expr
	}

	if exists != nil {
		// For EXISTS expressions, all we want to know is if there is at least one
		// result.
		if plan.Next() {
			return true, parser.MakeDBool(true)
		}
		v.err = plan.Err()
		if v.err != nil {
			return false, expr
		}
		return true, parser.MakeDBool(false)
	}

	columns, multipleRows := v.getSubqueryContext()
	if n := len(plan.Columns()); columns != n {
		switch columns {
		case 1:
			v.err = fmt.Errorf("subquery must return only one column, found %d", n)
		default:
			v.err = fmt.Errorf("subquery must return %d columns, found %d", columns, n)
		}
		return true, expr
	}

	var result parser.Expr
	if multipleRows {
		var rows parser.DTuple
		for plan.Next() {
			values := plan.Values()
			switch len(values) {
			case 1:
				// This seems hokey, but if we don't do this then the subquery expands
				// to a tuple of tuples instead of a tuple of values and an expression
				// like "k IN (SELECT foo FROM bar)" will fail because we're comparing
				// a single value against a tuple.
				rows = append(rows, values[0])
			default:
				// The result from plan.Values() is only valid until the next call to
				// plan.Next(), so make a copy.
				valuesCopy := make(parser.DTuple, len(values))
				copy(valuesCopy, values)
				rows = append(rows, &valuesCopy)
			}
		}
		rows.Normalize()
		result = &rows
	} else {
		result = parser.DNull
		for plan.Next() {
			values := plan.Values()
			switch len(values) {
			case 1:
				result = values[0]
			default:
				valuesCopy := make(parser.DTuple, len(values))
				copy(valuesCopy, values)
				result = &valuesCopy
			}
			if plan.Next() {
				v.err = fmt.Errorf("more than one row returned by a subquery used as an expression")
				return false, expr
			}
		}
	}

	v.err = plan.Err()
	if v.err != nil {
		return false, expr
	}
	return true, result
}
Beispiel #18
0
func simplifyOneOrExpr(left, right parser.TypedExpr) (parser.TypedExpr, parser.TypedExpr, bool) {
	lcmp, ok := left.(*parser.ComparisonExpr)
	if !ok {
		return left, right, true
	}
	rcmp, ok := right.(*parser.ComparisonExpr)
	if !ok {
		return left, right, true
	}
	lcmpLeft, lcmpRight := lcmp.TypedLeft(), lcmp.TypedRight()
	rcmpLeft, rcmpRight := rcmp.TypedLeft(), rcmp.TypedRight()
	if !isDatum(lcmpRight) || !isDatum(rcmpRight) {
		return parser.MakeDBool(true), nil, false
	}
	if !varEqual(lcmpLeft, rcmpLeft) {
		return left, right, true
	}

	if lcmp.Operator == parser.IsNot || rcmp.Operator == parser.IsNot {
		switch lcmp.Operator {
		case parser.Is:
			if lcmpRight == parser.DNull && rcmpRight == parser.DNull {
				// a IS NULL OR a IS NOT NULL
				return parser.MakeDBool(true), nil, true
			}
		case parser.IsNot:
			if lcmpRight == parser.DNull {
				switch rcmp.Operator {
				case parser.Is:
					if rcmpRight == parser.DNull {
						// a IS NOT NULL OR a IS NULL
						return parser.MakeDBool(true), nil, true
					}
				case parser.IsNot:
					if rcmpRight == parser.DNull {
						// a IS NOT NULL OR a IS NOT NULL
						return left, nil, true
					}
				}
			}
		}
		return left, right, true
	}

	if lcmp.Operator == parser.In || rcmp.Operator == parser.In {
		left, right = simplifyOneOrInExpr(lcmp, rcmp)
		return left, right, true
	}

	if reflect.TypeOf(lcmpRight) != reflect.TypeOf(rcmpRight) {
		allowCmp := false
		switch lcmp.Operator {
		case parser.EQ, parser.NE, parser.GT, parser.GE, parser.LT, parser.LE:
			switch rcmp.Operator {
			case parser.EQ, parser.NE, parser.GT, parser.GE, parser.LT, parser.LE:
				// Break, permitting heterogeneous comparison.
				allowCmp = true
			}
		}
		if !allowCmp {
			// If the types of the left and right datums are different, no
			// simplification is possible.
			return left, right, true
		}
	}

	ldatum := lcmpRight.(parser.Datum)
	rdatum := rcmpRight.(parser.Datum)
	cmp := ldatum.Compare(rdatum)

	// Determine which expression to use when either expression (left or right)
	// is valid as a return value but their types are different. The reason
	// to prefer a comparison between a column value and a datum of the same
	// type is that it makes index constraint construction easier.
	either := lcmp
	if !ldatum.TypeEqual(rdatum) {
		switch ta := lcmpLeft.(type) {
		case *qvalue:
			if ta.datum.TypeEqual(rdatum) {
				either = rcmp
			}
		}
	}

	// TODO(pmattis): Figure out how to generate this logic.
	switch lcmp.Operator {
	case parser.EQ:
		switch rcmp.Operator {
		case parser.EQ:
			// a = x OR a = y
			if cmp == 0 {
				// x = y
				return either, nil, true
			} else if cmp == 1 {
				// x > y
				ldatum, rdatum = rdatum, ldatum
			}
			return parser.NewTypedComparisonExpr(
				parser.In,
				lcmpLeft,
				&parser.DTuple{ldatum, rdatum},
			), nil, true
		case parser.NE:
			// a = x OR a != y
			if cmp == 0 {
				// x = y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			return right, nil, true
		case parser.GT:
			// a = x OR a > y
			if cmp == 1 {
				// x > y OR x = y
				return right, nil, true
			} else if cmp == 0 {
				return parser.NewTypedComparisonExpr(
					parser.GE,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			}
			return left, right, true
		case parser.GE:
			// a = x OR a >= y
			if cmp != -1 {
				// x >= y
				return right, nil, true
			}
			return left, right, true
		case parser.LT:
			// a = x OR a < y
			if cmp == -1 {
				// x < y OR x = y
				return right, nil, true
			} else if cmp == 0 {
				return parser.NewTypedComparisonExpr(
					parser.LE,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			}
			return left, right, true
		case parser.LE:
			// a = x OR a <= y
			if cmp != 1 {
				// x <= y
				return right, nil, true
			}
			return left, right, true
		}

	case parser.NE:
		switch rcmp.Operator {
		case parser.EQ:
			// a != x OR a = y
			if cmp == 0 {
				// x = y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x != y
			return left, nil, true
		case parser.NE:
			// a != x OR a != y
			if cmp == 0 {
				// x = y
				return either, nil, true
			}
			// x != y
			return makeIsNotNull(lcmpLeft), nil, true
		case parser.GT:
			// a != x OR a > y
			if cmp == 1 {
				// x > y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x <= y
			return left, nil, true
		case parser.GE:
			// a != x OR a >= y
			if cmp != -1 {
				// x >= y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x < y
			return left, nil, true
		case parser.LT:
			// a != x OR a < y
			if cmp == -1 {
				// x < y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x >= y
			return left, nil, true
		case parser.LE:
			// a != x OR a <= y
			if cmp != 1 {
				// x <= y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x > y
			return left, nil, true
		}

	case parser.GT:
		switch rcmp.Operator {
		case parser.EQ:
			// a > x OR a = y
			if cmp == -1 {
				// x < y
				return left, nil, true
			} else if cmp == 0 {
				return parser.NewTypedComparisonExpr(
					parser.GE,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			}
			// x > y
			return left, right, true
		case parser.NE:
			// a > x OR a != y
			if cmp == -1 {
				// x < y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x >= y
			return right, nil, true
		case parser.GT, parser.GE:
			// a > x OR (a > y OR a >= y)
			if cmp == -1 {
				return left, nil, true
			}
			return right, nil, true
		case parser.LT:
			// a > x OR a < y
			if cmp == 0 {
				// x = y
				return parser.NewTypedComparisonExpr(
					parser.NE,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			} else if cmp == -1 {
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x != y
			return left, right, true
		case parser.LE:
			// a > x OR a <= y
			if cmp != 1 {
				// x = y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x != y
			return left, right, true
		}

	case parser.GE:
		switch rcmp.Operator {
		case parser.EQ:
			// a >= x OR a = y
			if cmp != 1 {
				// x >. y
				return left, nil, true
			}
			// x < y
			return left, right, true
		case parser.NE:
			// a >= x OR a != y
			if cmp != 1 {
				// x <= y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x > y
			return right, nil, true
		case parser.GT:
			// a >= x OR a > y
			if cmp != 1 {
				// x <= y
				return left, nil, true
			}
			// x > y
			return right, nil, true
		case parser.GE:
			// a >= x OR a >= y
			if cmp == -1 {
				// x < y
				return left, nil, true
			}
			// x >= y
			return right, nil, true
		case parser.LT, parser.LE:
			// a >= x OR a < y
			if cmp != 1 {
				// x <= y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x > y
			return left, right, true
		}

	case parser.LT:
		switch rcmp.Operator {
		case parser.EQ:
			// a < x OR a = y
			if cmp == 0 {
				// x = y
				return parser.NewTypedComparisonExpr(
					parser.LE,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			} else if cmp == 1 {
				// x > y
				return left, nil, true
			}
			// x < y
			return left, right, true
		case parser.NE:
			// a < x OR a != y
			if cmp == 1 {
				return makeIsNotNull(lcmpLeft), nil, true
			}
			return right, nil, true
		case parser.GT:
			// a < x OR a > y
			if cmp == 0 {
				// x = y
				return parser.NewTypedComparisonExpr(
					parser.NE,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			} else if cmp == 1 {
				// x > y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			return left, right, true
		case parser.GE:
			// a < x OR a >= y
			if cmp == -1 {
				// x < y
				return left, right, true
			}
			// x >= y
			return makeIsNotNull(lcmpLeft), nil, true
		case parser.LT, parser.LE:
			// a < x OR (a < y OR a <= y)
			if cmp == 1 {
				// x > y
				return left, nil, true
			}
			// x < y
			return right, nil, true
		}

	case parser.LE:
		switch rcmp.Operator {
		case parser.EQ:
			// a <= x OR a = y
			if cmp == -1 {
				// x < y
				return left, right, true
			}
			// x >= y
			return left, nil, true
		case parser.NE:
			// a <= x OR a != y
			if cmp != -1 {
				// x >= y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x < y
			return right, nil, true
		case parser.GT, parser.GE:
			// a <= x OR (a > y OR a >= y)
			if cmp != -1 {
				// x >= y
				return makeIsNotNull(lcmpLeft), nil, true
			}
			// x < y
			return left, right, true
		case parser.LT, parser.LE:
			// a <= x OR a < y
			if cmp == -1 {
				// x < y
				return right, nil, true
			}
			// x >= y
			return left, nil, true
		}

	case parser.Is:
		switch rcmp.Operator {
		case parser.Is:
			if lcmpRight == parser.DNull && rcmpRight == parser.DNull {
				// a IS NULL OR a IS NULL
				return left, nil, true
			}
		}
	}

	return parser.MakeDBool(true), nil, false
}
Beispiel #19
0
func simplifyOneAndInExpr(left, right *parser.ComparisonExpr) (parser.TypedExpr, parser.TypedExpr) {
	if left.Operator != parser.In && right.Operator != parser.In {
		panic(fmt.Sprintf("IN expression required: %s vs %s", left, right))
	}

	origLeft, origRight := left, right

	switch left.Operator {
	case parser.EQ, parser.NE, parser.GT, parser.GE, parser.LT, parser.LE, parser.Is:
		switch right.Operator {
		case parser.In:
			left, right = right, left
		}
		fallthrough

	case parser.In:
		ltuple := *left.Right.(*parser.DTuple)
		switch right.Operator {
		case parser.Is:
			if right.Right == parser.DNull {
				return parser.MakeDBool(false), nil
			}

		case parser.EQ, parser.NE, parser.GT, parser.GE, parser.LT, parser.LE:
			// Our tuple will be sorted (see simplifyComparisonExpr). Binary search
			// for the right datum.
			datum := right.Right.(parser.Datum)
			i := sort.Search(len(ltuple), func(i int) bool {
				return ltuple[i].(parser.Datum).Compare(datum) >= 0
			})

			switch right.Operator {
			case parser.EQ:
				if i < len(ltuple) && ltuple[i].Compare(datum) == 0 {
					return right, nil
				}
				return parser.MakeDBool(false), nil

			case parser.NE:
				if i < len(ltuple) && ltuple[i].Compare(datum) == 0 {
					if len(ltuple) < 2 {
						return parser.MakeDBool(false), nil
					}
					ltuple = remove(ltuple, i)
				}
				return parser.NewTypedComparisonExpr(
					parser.In,
					left.TypedLeft(),
					&ltuple,
				), nil

			case parser.GT:
				if i < len(ltuple) {
					if ltuple[i].Compare(datum) == 0 {
						ltuple = ltuple[i+1:]
					} else {
						ltuple = ltuple[i:]
					}
					if len(ltuple) > 0 {
						return parser.NewTypedComparisonExpr(
							parser.In,
							left.TypedLeft(),
							&ltuple,
						), nil
					}
				}
				return parser.MakeDBool(false), nil

			case parser.GE:
				if i < len(ltuple) {
					ltuple = ltuple[i:]
					if len(ltuple) > 0 {
						return parser.NewTypedComparisonExpr(
							parser.In,
							left.TypedLeft(),
							&ltuple,
						), nil
					}
				}
				return parser.MakeDBool(false), nil

			case parser.LT:
				if i < len(ltuple) {
					if i == 0 {
						return parser.MakeDBool(false), nil
					}
					ltuple = ltuple[:i]
					return parser.NewTypedComparisonExpr(
						parser.In,
						left.TypedLeft(),
						&ltuple,
					), nil
				}
				return left, nil

			case parser.LE:
				if i < len(ltuple) {
					if ltuple[i].Compare(datum) == 0 {
						i++
					}
					if i == 0 {
						return parser.MakeDBool(false), nil
					}
					ltuple = ltuple[:i]
					return parser.NewTypedComparisonExpr(
						parser.In,
						left.TypedLeft(),
						&ltuple,
					), nil
				}
				return left, nil
			}

		case parser.In:
			// Both of our tuples are sorted. Intersect the lists.
			rtuple := *right.Right.(*parser.DTuple)
			intersection := intersectSorted(ltuple, rtuple)
			if len(*intersection) == 0 {
				return parser.MakeDBool(false), nil
			}
			return parser.NewTypedComparisonExpr(
				parser.In,
				left.TypedLeft(),
				intersection,
			), nil
		}
	}

	return origLeft, origRight
}
Beispiel #20
0
func simplifyOneAndExpr(left, right parser.TypedExpr) (parser.TypedExpr, parser.TypedExpr, bool) {
	lcmp, ok := left.(*parser.ComparisonExpr)
	if !ok {
		return left, right, true
	}
	rcmp, ok := right.(*parser.ComparisonExpr)
	if !ok {
		return left, right, true
	}
	lcmpLeft, lcmpRight := lcmp.TypedLeft(), lcmp.TypedRight()
	rcmpLeft, rcmpRight := rcmp.TypedLeft(), rcmp.TypedRight()
	if !isDatum(lcmpRight) || !isDatum(rcmpRight) {
		return parser.MakeDBool(true), nil, false
	}
	if !varEqual(lcmpLeft, rcmpLeft) {
		return left, right, true
	}

	if lcmp.Operator == parser.IsNot || rcmp.Operator == parser.IsNot {
		switch lcmp.Operator {
		case parser.EQ, parser.GT, parser.GE, parser.LT, parser.LE, parser.In:
			if rcmpRight == parser.DNull {
				// a <cmp> x AND a IS NOT NULL
				return left, nil, true
			}
		case parser.Is:
			if lcmpRight == parser.DNull && rcmpRight == parser.DNull {
				// a IS NULL AND a IS NOT NULL
				return parser.MakeDBool(false), nil, true
			}
		case parser.IsNot:
			if lcmpRight == parser.DNull {
				switch rcmp.Operator {
				case parser.EQ, parser.GT, parser.GE, parser.LT, parser.LE, parser.In:
					// a IS NOT NULL AND a <cmp> x
					return right, nil, true
				case parser.Is:
					if rcmpRight == parser.DNull {
						// a IS NOT NULL AND a IS NULL
						return parser.MakeDBool(false), nil, true
					}
				case parser.IsNot:
					if rcmpRight == parser.DNull {
						// a IS NOT NULL AND a IS NOT NULL
						return left, nil, true
					}
				}
			}
		}
		return left, right, true
	}

	if lcmp.Operator == parser.In || rcmp.Operator == parser.In {
		left, right = simplifyOneAndInExpr(lcmp, rcmp)
		return left, right, true
	}

	if reflect.TypeOf(lcmpRight) != reflect.TypeOf(rcmpRight) {
		allowCmp := false
		switch lcmp.Operator {
		case parser.EQ, parser.NE, parser.GT, parser.GE, parser.LT, parser.LE:
			switch rcmp.Operator {
			case parser.EQ, parser.NE, parser.GT, parser.GE, parser.LT, parser.LE:
				// Break, permitting heterogeneous comparison.
				allowCmp = true
			}
		}
		if !allowCmp {
			if lcmp.Operator == parser.Is && lcmpRight == parser.DNull {
				// a IS NULL AND a <cmp> x
				return parser.MakeDBool(false), nil, true
			}
			if rcmp.Operator == parser.Is && rcmpRight == parser.DNull {
				// a <cmp> x AND a IS NULL
				return parser.MakeDBool(false), nil, true
			}
			// Note that "a IS NULL and a IS NULL" cannot happen here because
			// "reflect.TypeOf(NULL) == reflect.TypeOf(NULL)".
			return left, right, true
		}
	}

	ldatum := lcmpRight.(parser.Datum)
	rdatum := rcmpRight.(parser.Datum)
	cmp := ldatum.Compare(rdatum)

	// Determine which expression to use when either expression (left or right)
	// is valid as a return value but their types are different. The reason
	// to prefer a comparison between a column value and a datum of the same
	// type is that it makes index constraint construction easier.
	either := lcmp
	if !ldatum.TypeEqual(rdatum) {
		switch ta := lcmpLeft.(type) {
		case *qvalue:
			if ta.datum.TypeEqual(rdatum) {
				either = rcmp
			}
		}
	}

	// TODO(pmattis): Figure out how to generate this logic.
	switch lcmp.Operator {
	case parser.EQ:
		switch rcmp.Operator {
		case parser.EQ:
			// a = x AND a = y
			if cmp == 0 {
				// x = y
				return either, nil, true
			}
			return parser.MakeDBool(false), nil, true
		case parser.NE:
			// a = x AND a != y
			if cmp == 0 {
				// x = y
				return parser.MakeDBool(false), nil, true
			}
			return left, nil, true
		case parser.GT, parser.GE:
			// a = x AND (a > y OR a >= y)
			if cmp == -1 || (cmp == 0 && rcmp.Operator == parser.GT) {
				// x < y OR x = y
				return parser.MakeDBool(false), nil, true
			}
			return left, nil, true
		case parser.LT, parser.LE:
			// a = x AND (a < y OR a <= y)
			if cmp == 1 || (cmp == 0 && rcmp.Operator == parser.LT) {
				// x > y OR x = y
				return parser.MakeDBool(false), nil, true
			}
			return left, nil, true
		}

	case parser.NE:
		switch rcmp.Operator {
		case parser.EQ:
			// a != x AND a = y
			if cmp == 0 {
				// x = y
				return parser.MakeDBool(false), nil, true
			}
			return right, nil, true
		case parser.NE:
			// a != x AND a != y
			if cmp == 0 {
				// x = y
				return either, nil, true
			}
			return left, right, true
		case parser.GT:
			// a != x AND a > y
			return right, nil, cmp <= 0
		case parser.LT:
			// a != x AND a < y
			return right, nil, cmp >= 0
		case parser.GE:
			// a != x AND a >= y
			if cmp == 0 {
				// x = y
				return parser.NewTypedComparisonExpr(
					parser.GT,
					rcmpLeft,
					either.TypedRight(),
				), nil, true
			}
			// x != y
			return right, nil, cmp == -1
		case parser.LE:
			// a != x AND a <= y
			if cmp == 0 {
				// x = y
				return parser.NewTypedComparisonExpr(
					parser.LT,
					rcmpLeft,
					either.TypedRight(),
				), nil, true
			}
			// x != y
			return right, nil, cmp == +1
		}

	case parser.GT:
		switch rcmp.Operator {
		case parser.EQ:
			// a > x AND a = y
			if cmp != -1 {
				// x >= y
				return parser.MakeDBool(false), nil, true
			}
			// x < y
			return right, nil, true
		case parser.NE:
			// a > x AND a != y
			return left, nil, cmp >= 0
		case parser.GT, parser.GE:
			// a > x AND (a > y OR a >= y)
			if cmp != -1 {
				// x >= y
				return left, nil, true
			}
			// x < y
			return right, nil, true
		case parser.LT, parser.LE:
			// a > x AND (a < y OR a <= y)
			if cmp == -1 {
				// x < y
				return left, right, true
			}
			// x >= y
			return parser.MakeDBool(false), nil, true
		}

	case parser.GE:
		switch rcmp.Operator {
		case parser.EQ:
			// a >= x AND a = y
			if cmp == 1 {
				// x > y
				return parser.MakeDBool(false), nil, true
			}
			// x <= y
			return right, nil, true
		case parser.NE:
			// a >= x AND x != y
			if cmp == 0 {
				// x = y
				return parser.NewTypedComparisonExpr(
					parser.GT,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			}
			// x != y
			return left, nil, cmp == +1
		case parser.GT, parser.GE:
			// a >= x AND (a > y OR a >= y)
			if cmp == -1 || (cmp == 0 && rcmp.Operator == parser.GT) {
				// x < y
				return right, nil, true
			}
			// x >= y
			return left, nil, true
		case parser.LT:
			// a >= x AND a < y
			if cmp == -1 {
				// x < y
				return left, right, true
			}
			// x >= y
			return parser.MakeDBool(false), nil, true
		case parser.LE:
			// a >= x AND a <= y
			if cmp == -1 {
				// x < y
				return left, right, true
			} else if cmp == 0 {
				// x = y
				return parser.NewTypedComparisonExpr(
					parser.EQ,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			}
			// x > y
			return parser.MakeDBool(false), nil, true
		}

	case parser.LT:
		switch rcmp.Operator {
		case parser.EQ:
			// a < x AND a = y
			if cmp != 1 {
				// x <= y
				return parser.MakeDBool(false), nil, true
			}
			// x > y
			return right, nil, true
		case parser.NE:
			// a < x AND a != y
			return left, nil, cmp <= 0
		case parser.GT, parser.GE:
			// a < x AND (a > y OR a >= y)
			if cmp == 1 {
				// x > y
				return left, right, true
			}
			// x <= y
			return parser.MakeDBool(false), nil, true
		case parser.LT, parser.LE:
			// a < x AND (a < y OR a <= y)
			if cmp != 1 {
				// x <= y
				return left, nil, true
			}
			// x > y
			return right, nil, true
		}

	case parser.LE:
		switch rcmp.Operator {
		case parser.EQ:
			// a <= x AND a = y
			if cmp == -1 {
				// x < y
				return parser.MakeDBool(false), nil, true
			}
			// x >= y
			return right, nil, true
		case parser.NE:
			// a <= x AND a != y
			if cmp == 0 {
				// x = y
				return parser.NewTypedComparisonExpr(
					parser.LT,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			}
			// x != y
			return left, nil, cmp == -1
		case parser.GT:
			// a <= x AND a > y
			if cmp == 1 {
				// x > y
				return left, right, true
			}
			return parser.MakeDBool(false), nil, true
		case parser.GE:
			// a <= x AND a >= y
			if cmp == +1 {
				// x > y
				return left, right, true
			} else if cmp == 0 {
				// x = y
				return parser.NewTypedComparisonExpr(
					parser.EQ,
					lcmpLeft,
					either.TypedRight(),
				), nil, true
			}
			// x < y
			return parser.MakeDBool(false), nil, true
		case parser.LT, parser.LE:
			// a <= x AND (a > y OR a >= y)
			if cmp == 1 || (cmp == 0 && rcmp.Operator == parser.LT) {
				// x > y
				return right, nil, true
			}
			// x <= y
			return left, nil, true
		}

	case parser.Is:
		switch rcmp.Operator {
		case parser.Is:
			if lcmpRight == parser.DNull && rcmpRight == parser.DNull {
				// a IS NULL AND a IS NULL
				return left, nil, true
			}
		}
	}

	return parser.MakeDBool(true), nil, false
}
Beispiel #21
0
// decodeOidDatum decodes bytes with specified Oid and format code into
// a datum.
func decodeOidDatum(id oid.Oid, code formatCode, b []byte) (parser.Datum, error) {
	var d parser.Datum
	switch id {
	case oid.T_bool:
		switch code {
		case formatText:
			v, err := strconv.ParseBool(string(b))
			if err != nil {
				return d, err
			}
			d = parser.MakeDBool(parser.DBool(v))
		default:
			return d, fmt.Errorf("unsupported bool format code: %d", code)
		}
	case oid.T_int2:
		switch code {
		case formatText:
			i, err := strconv.ParseInt(string(b), 10, 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		case formatBinary:
			var i int16
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &i)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		default:
			return d, fmt.Errorf("unsupported int2 format code: %d", code)
		}
	case oid.T_int4:
		switch code {
		case formatText:
			i, err := strconv.ParseInt(string(b), 10, 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		case formatBinary:
			var i int32
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &i)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		default:
			return d, fmt.Errorf("unsupported int4 format code: %d", code)
		}
	case oid.T_int8:
		switch code {
		case formatText:
			i, err := strconv.ParseInt(string(b), 10, 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		case formatBinary:
			var i int64
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &i)
			if err != nil {
				return d, err
			}
			d = parser.NewDInt(parser.DInt(i))
		default:
			return d, fmt.Errorf("unsupported int8 format code: %d", code)
		}
	case oid.T_float4:
		switch code {
		case formatText:
			f, err := strconv.ParseFloat(string(b), 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDFloat(parser.DFloat(f))
		case formatBinary:
			var f float32
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &f)
			if err != nil {
				return d, err
			}
			d = parser.NewDFloat(parser.DFloat(f))
		default:
			return d, fmt.Errorf("unsupported float4 format code: %d", code)
		}
	case oid.T_float8:
		switch code {
		case formatText:
			f, err := strconv.ParseFloat(string(b), 64)
			if err != nil {
				return d, err
			}
			d = parser.NewDFloat(parser.DFloat(f))
		case formatBinary:
			var f float64
			err := binary.Read(bytes.NewReader(b), binary.BigEndian, &f)
			if err != nil {
				return d, err
			}
			d = parser.NewDFloat(parser.DFloat(f))
		default:
			return d, fmt.Errorf("unsupported float8 format code: %d", code)
		}
	case oid.T_numeric:
		switch code {
		case formatText:
			dd := &parser.DDecimal{}
			if _, ok := dd.SetString(string(b)); !ok {
				return nil, fmt.Errorf("could not parse string %q as decimal", b)
			}
			d = dd
		default:
			return d, fmt.Errorf("unsupported numeric format code: %d", code)
		}
	case oid.T_text, oid.T_varchar:
		switch code {
		case formatText:
			d = parser.NewDString(string(b))
		default:
			return d, fmt.Errorf("unsupported text format code: %d", code)
		}
	case oid.T_bytea:
		switch code {
		case formatText:
			// http://www.postgresql.org/docs/current/static/datatype-binary.html#AEN5667
			// Code cribbed from github.com/lib/pq.

			// We only support hex encoding.
			if len(b) >= 2 && bytes.Equal(b[:2], []byte("\\x")) {
				b = b[2:] // trim off leading "\\x"
				result := make([]byte, hex.DecodedLen(len(b)))
				_, err := hex.Decode(result, b)
				if err != nil {
					return d, err
				}
				d = parser.NewDBytes(parser.DBytes(result))
			} else {
				return d, fmt.Errorf("unsupported bytea encoding: %q", b)
			}
		case formatBinary:
			d = parser.NewDBytes(parser.DBytes(b))
		default:
			return d, fmt.Errorf("unsupported bytea format code: %d", code)
		}
	case oid.T_timestamp, oid.T_timestamptz:
		switch code {
		case formatText:
			ts, err := parseTs(string(b))
			if err != nil {
				return d, fmt.Errorf("could not parse string %q as timestamp", b)
			}
			d = &parser.DTimestamp{Time: ts}
		case formatBinary:
			return d, fmt.Errorf("unsupported timestamp format code: %d", code)
		}
	case oid.T_date:
		switch code {
		case formatText:
			ts, err := parseTs(string(b))
			if err != nil {
				return d, fmt.Errorf("could not parse string %q as date", b)
			}
			daysSinceEpoch := ts.Unix() / secondsInDay
			d = parser.NewDDate(parser.DDate(daysSinceEpoch))
		case formatBinary:
			return d, fmt.Errorf("unsupported date format code: %d", code)
		}
	default:
		return d, fmt.Errorf("unsupported OID: %v", id)
	}
	return d, nil
}
Beispiel #22
0
func (s *subquery) doEval() (parser.Datum, error) {
	var result parser.Datum
	switch s.execMode {
	case execModeExists:
		// For EXISTS expressions, all we want to know is if there is at least one
		// result.
		next, err := s.plan.Next()
		if s.err = err; err != nil {
			return result, err
		}
		if next {
			result = parser.MakeDBool(true)
		}
		if result == nil {
			result = parser.MakeDBool(false)
		}

	case execModeAllRows:
		var rows parser.DTuple
		next, err := s.plan.Next()
		for ; next; next, err = s.plan.Next() {
			values := s.plan.Values()
			switch len(values) {
			case 1:
				// This seems hokey, but if we don't do this then the subquery expands
				// to a tuple of tuples instead of a tuple of values and an expression
				// like "k IN (SELECT foo FROM bar)" will fail because we're comparing
				// a single value against a tuple.
				rows = append(rows, values[0])
			default:
				// The result from plan.Values() is only valid until the next call to
				// plan.Next(), so make a copy.
				valuesCopy := make(parser.DTuple, len(values))
				copy(valuesCopy, values)
				rows = append(rows, &valuesCopy)
			}
		}
		if s.err = err; err != nil {
			return result, err
		}
		if s.wantNormalized {
			rows.Normalize()
		}
		result = &rows

	case execModeOneRow:
		result = parser.DNull
		next, err := s.plan.Next()
		if s.err = err; err != nil {
			return result, err
		}
		if next {
			values := s.plan.Values()
			switch len(values) {
			case 1:
				result = values[0]
			default:
				valuesCopy := make(parser.DTuple, len(values))
				copy(valuesCopy, values)
				result = &valuesCopy
			}
			another, err := s.plan.Next()
			if s.err = err; err != nil {
				return result, err
			}
			if another {
				s.err = fmt.Errorf("more than one row returned by a subquery used as an expression")
				return result, s.err
			}
		}
	}

	return result, nil
}
Beispiel #23
0
func simplifyComparisonExpr(n *parser.ComparisonExpr) (parser.TypedExpr, bool) {
	// NormalizeExpr will have left comparisons in the form "<var> <op>
	// <datum>" unless they could not be simplified further in which case
	// simplifyExpr cannot handle them. For example, "lower(a) = 'foo'"
	left, right := n.TypedLeft(), n.TypedRight()
	if isVar(left) && isDatum(right) {
		if right == parser.DNull {
			switch n.Operator {
			case parser.IsNotDistinctFrom:
				switch left.(type) {
				case *qvalue, *parser.IndexedVar:
					// Transform "a IS NOT DISTINCT FROM NULL" into "a IS NULL".
					return parser.NewTypedComparisonExpr(
						parser.Is,
						left,
						right,
					), true
				}
			case parser.IsDistinctFrom:
				switch left.(type) {
				case *qvalue, *parser.IndexedVar:
					// Transform "a IS DISTINCT FROM NULL" into "a IS NOT NULL".
					return parser.NewTypedComparisonExpr(
						parser.IsNot,
						left,
						right,
					), true
				}
			case parser.Is, parser.IsNot:
				switch left.(type) {
				case *qvalue, *parser.IndexedVar:
					// "a IS {,NOT} NULL" can be used during index selection to restrict
					// the range of scanned keys.
					return n, true
				}
			default:
				// All of the remaining comparison operators have the property that when
				// comparing to NULL they evaluate to NULL (see evalComparisonOp). NULL is
				// not the same as false, but in the context of a WHERE clause, NULL is
				// considered not-true which is the same as false.
				return parser.MakeDBool(false), true
			}
		}

		switch n.Operator {
		case parser.EQ:
			// Translate "(a, b) = (1, 2)" to "(a, b) IN ((1, 2))".
			switch left.(type) {
			case *parser.Tuple:
				return parser.NewTypedComparisonExpr(
					parser.In,
					left,
					&parser.DTuple{right.(parser.Datum)},
				), true
			}
			return n, true
		case parser.NE, parser.GE, parser.LE:
			return n, true
		case parser.GT:
			// This simplification is necessary so that subsequent transformation of
			// > constraint to >= can use Datum.Next without concern about whether a
			// next value exists. Note that if the variable (n.Left) is NULL, this
			// comparison would evaluate to NULL which is equivalent to false for a
			// boolean expression.
			if right.(parser.Datum).IsMax() {
				return parser.MakeDBool(false), true
			}
			return n, true
		case parser.LT:
			// Note that if the variable is NULL, this would evaluate to NULL which
			// would equivalent to false for a boolean expression.
			if right.(parser.Datum).IsMin() {
				return parser.MakeDBool(false), true
			}
			return n, true
		case parser.In, parser.NotIn:
			tuple := *right.(*parser.DTuple)
			if len(tuple) == 0 {
				return parser.MakeDBool(false), true
			}
			return n, true
		case parser.Like:
			// a LIKE 'foo%' -> a >= "foo" AND a < "fop"
			if d, ok := right.(*parser.DString); ok {
				if i := strings.IndexAny(string(*d), "_%"); i >= 0 {
					return makePrefixRange((*d)[:i], left, false), false
				}
				return makePrefixRange(*d, left, true), false
			}
			// TODO(pmattis): Support parser.DBytes?
		case parser.SimilarTo:
			// a SIMILAR TO "foo.*" -> a >= "foo" AND a < "fop"
			if d, ok := right.(*parser.DString); ok {
				pattern := parser.SimilarEscape(string(*d))
				if re, err := regexp.Compile(pattern); err == nil {
					prefix, complete := re.LiteralPrefix()
					return makePrefixRange(parser.DString(prefix), left, complete), false
				}
			}
			// TODO(pmattis): Support parser.DBytes?
		}
	}
	return parser.MakeDBool(true), false
}
Beispiel #24
0
func dumpTable(w io.Writer, conn *sqlConn, origDBName, origTableName string) error {
	const limit = 100

	// Escape names since they can't be used in placeholders.
	dbname := parser.Name(origDBName).String()
	tablename := parser.Name(origTableName).String()

	if err := conn.Exec(fmt.Sprintf("SET DATABASE = %s", dbname), nil); err != nil {
		return err
	}

	// Fetch all table metadata in a transaction and its time to guarantee it
	// doesn't change between the various SHOW statements.
	if err := conn.Exec("BEGIN", nil); err != nil {
		return err
	}

	vals, err := conn.QueryRow("SELECT cluster_logical_timestamp()::int", nil)
	if err != nil {
		return err
	}
	clusterTSStart := vals[0].(int64)
	clusterTS := time.Unix(0, clusterTSStart).Format(time.RFC3339Nano)

	// Fetch table descriptor.
	vals, err = conn.QueryRow(`
		SELECT descriptor
		FROM system.descriptor
		JOIN system.namespace tables
			ON tables.id = descriptor.id
		JOIN system.namespace dbs
			ON dbs.id = tables.parentid
		WHERE tables.name = $1 AND dbs.name = $2`,
		[]driver.Value{origTableName, origDBName})
	if err == io.EOF {
		return errors.Errorf("unknown database or table %s.%s", origTableName, origDBName)
	} else if err != nil {
		return err
	}
	b := vals[0].([]byte)
	var desc sqlbase.Descriptor
	if err := proto.Unmarshal(b, &desc); err != nil {
		return err
	}
	table := desc.GetTable()
	if table == nil {
		return errors.New("internal error: expected table descriptor")
	}

	coltypes := make(map[string]string)
	for _, c := range table.Columns {
		coltypes[c.Name] = c.Type.SQLString()
	}

	primaryIndex := table.PrimaryIndex.Name
	index := table.PrimaryIndex.ColumnNames
	indexes := strings.Join(index, ", ")

	// Build the SELECT query.
	var sbuf bytes.Buffer
	fmt.Fprintf(&sbuf, "SELECT %s, * FROM %s@%s AS OF SYSTEM TIME '%s'", indexes, tablename, primaryIndex, clusterTS)

	var wbuf bytes.Buffer
	fmt.Fprintf(&wbuf, " WHERE ROW (%s) > ROW (", indexes)
	for i := range index {
		if i > 0 {
			wbuf.WriteString(", ")
		}
		fmt.Fprintf(&wbuf, "$%d", i+1)
	}
	wbuf.WriteString(")")
	// No WHERE clause first time, so add a place to inject it.
	fmt.Fprintf(&sbuf, "%%s ORDER BY %s LIMIT %d", indexes, limit)
	bs := sbuf.String()

	vals, err = conn.QueryRow(fmt.Sprintf("SHOW CREATE TABLE %s", tablename), nil)
	if err != nil {
		return err
	}
	create := vals[1].([]byte)
	if _, err := w.Write(create); err != nil {
		return err
	}
	if _, err := w.Write([]byte(";\n")); err != nil {
		return err
	}

	if err := conn.Exec("COMMIT", nil); err != nil {
		return err
	}

	// pk holds the last values of the fetched primary keys
	var pk []driver.Value
	q := fmt.Sprintf(bs, "")
	for {
		rows, err := conn.Query(q, pk)
		if err != nil {
			return err
		}
		cols := rows.Columns()
		pkcols := cols[:len(index)]
		cols = cols[len(index):]
		inserts := make([][]string, 0, limit)
		i := 0
		for i < limit {
			vals := make([]driver.Value, len(cols)+len(pkcols))
			if err := rows.Next(vals); err == io.EOF {
				break
			} else if err != nil {
				return err
			}
			if pk == nil {
				q = fmt.Sprintf(bs, wbuf.String())
			}
			pk = vals[:len(index)]
			vals = vals[len(index):]
			ivals := make([]string, len(vals))
			// Values need to be correctly encoded for INSERT statements in a text file.
			for si, sv := range vals {
				switch t := sv.(type) {
				case nil:
					ivals[si] = "NULL"
				case bool:
					ivals[si] = parser.MakeDBool(parser.DBool(t)).String()
				case int64:
					ivals[si] = parser.NewDInt(parser.DInt(t)).String()
				case float64:
					ivals[si] = parser.NewDFloat(parser.DFloat(t)).String()
				case []byte:
					switch ct := coltypes[cols[si]]; ct {
					case "INTERVAL":
						ivals[si] = fmt.Sprintf("'%s'", t)
					case "DECIMAL":
						ivals[si] = fmt.Sprintf("%s", t)
					default:
						// STRING and BYTES types can have optional length suffixes, so only examine
						// the prefix of the type.
						if strings.HasPrefix(coltypes[cols[si]], "STRING") {
							ivals[si] = parser.NewDString(string(t)).String()
						} else if strings.HasPrefix(coltypes[cols[si]], "BYTES") {
							ivals[si] = parser.NewDBytes(parser.DBytes(t)).String()
						} else {
							panic(errors.Errorf("unknown []byte type: %s, %v: %s", t, cols[si], coltypes[cols[si]]))
						}
					}
				case time.Time:
					var d parser.Datum
					ct := coltypes[cols[si]]
					switch ct {
					case "DATE":
						d = parser.NewDDateFromTime(t, time.UTC)
					case "TIMESTAMP":
						d = parser.MakeDTimestamp(t, time.Nanosecond)
					case "TIMESTAMP WITH TIME ZONE":
						d = parser.MakeDTimestampTZ(t, time.Nanosecond)
					default:
						panic(errors.Errorf("unknown timestamp type: %s, %v: %s", t, cols[si], coltypes[cols[si]]))
					}
					ivals[si] = fmt.Sprintf("'%s'", d)
				default:
					panic(errors.Errorf("unknown field type: %T (%s)", t, cols[si]))
				}
			}
			inserts = append(inserts, ivals)
			i++
		}
		for si, sv := range pk {
			b, ok := sv.([]byte)
			if ok && strings.HasPrefix(coltypes[pkcols[si]], "STRING") {
				// Primary key strings need to be converted to a go string, but not SQL
				// encoded since they aren't being written to a text file.
				pk[si] = string(b)
			}
		}
		if err := rows.Close(); err != nil {
			return err
		}
		if i == 0 {
			break
		}
		fmt.Fprintf(w, "\nINSERT INTO %s VALUES", tablename)
		for idx, values := range inserts {
			if idx > 0 {
				fmt.Fprint(w, ",")
			}
			fmt.Fprint(w, "\n\t(")
			for vi, v := range values {
				if vi > 0 {
					fmt.Fprint(w, ", ")
				}
				fmt.Fprint(w, v)
			}
			fmt.Fprint(w, ")")
		}
		fmt.Fprintln(w, ";")
		if i < limit {
			break
		}
	}
	return nil
}
Beispiel #25
0
func TestValues(t *testing.T) {
	defer leaktest.AfterTest(t)()

	p := makePlanner()

	vInt := int64(5)
	vNum := 3.14159
	vStr := "two furs one cub"
	vBool := true

	unsupp := &parser.RangeCond{}

	intVal := func(v int64) *parser.NumVal {
		return &parser.NumVal{Value: constant.MakeInt64(v)}
	}
	floatVal := func(f float64) *parser.CastExpr {
		return &parser.CastExpr{
			Expr: &parser.NumVal{Value: constant.MakeFloat64(f)},
			Type: &parser.FloatColType{},
		}
	}
	asRow := func(datums ...parser.Datum) []parser.DTuple {
		return []parser.DTuple{datums}
	}

	makeValues := func(tuples ...*parser.Tuple) *parser.ValuesClause {
		return &parser.ValuesClause{Tuples: tuples}
	}
	makeTuple := func(exprs ...parser.Expr) *parser.Tuple {
		return &parser.Tuple{Exprs: exprs}
	}

	testCases := []struct {
		stmt *parser.ValuesClause
		rows []parser.DTuple
		ok   bool
	}{
		{
			makeValues(makeTuple(intVal(vInt))),
			asRow(parser.NewDInt(parser.DInt(vInt))),
			true,
		},
		{
			makeValues(makeTuple(intVal(vInt), intVal(vInt))),
			asRow(parser.NewDInt(parser.DInt(vInt)), parser.NewDInt(parser.DInt(vInt))),
			true,
		},
		{
			makeValues(makeTuple(floatVal(vNum))),
			asRow(parser.NewDFloat(parser.DFloat(vNum))),
			true,
		},
		{
			makeValues(makeTuple(parser.NewDString(vStr))),
			asRow(parser.NewDString(vStr)),
			true,
		},
		{
			makeValues(makeTuple(parser.NewDBytes(parser.DBytes(vStr)))),
			asRow(parser.NewDBytes(parser.DBytes(vStr))),
			true,
		},
		{
			makeValues(makeTuple(parser.MakeDBool(parser.DBool(vBool)))),
			asRow(parser.MakeDBool(parser.DBool(vBool))),
			true,
		},
		{
			makeValues(makeTuple(unsupp)),
			nil,
			false,
		},
	}

	for i, tc := range testCases {
		plan, err := func() (_ planNode, err error) {
			defer func() {
				if r := recover(); r != nil {
					err = errors.Errorf("%v", r)
				}
			}()
			return p.ValuesClause(tc.stmt, nil)
		}()
		if err == nil != tc.ok {
			t.Errorf("%d: error_expected=%t, but got error %v", i, tc.ok, err)
		}
		if plan != nil {
			if err := plan.expandPlan(); err != nil {
				t.Errorf("%d: unexpected error in expandPlan: %v", i, err)
				continue
			}
			if err := plan.Start(); err != nil {
				t.Errorf("%d: unexpected error in Start: %v", i, err)
				continue
			}
			var rows []parser.DTuple
			next, err := plan.Next()
			for ; next; next, err = plan.Next() {
				rows = append(rows, plan.Values())
			}
			if err != nil {
				t.Error(err)
				continue
			}
			if !reflect.DeepEqual(rows, tc.rows) {
				t.Errorf("%d: expected rows:\n%+v\nactual rows:\n%+v", i, tc.rows, rows)
			}
		}
	}
}
Beispiel #26
0
func dumpTable(w io.Writer, conn *sqlConn, origDBName, origTableName string) error {
	const limit = 100

	// Escape names since they can't be used in placeholders.
	dbname := parser.Name(origDBName).String()
	tablename := parser.Name(origTableName).String()

	if err := conn.Exec(fmt.Sprintf("SET DATABASE = %s", dbname), nil); err != nil {
		return err
	}

	// Fetch all table metadata in a transaction and its time to guarantee it
	// doesn't change between the various SHOW statements.
	if err := conn.Exec("BEGIN", nil); err != nil {
		return err
	}

	vals, err := conn.QueryRow("SELECT cluster_logical_timestamp()::int", nil)
	if err != nil {
		return err
	}
	clusterTSStart := vals[0].(int64)
	clusterTS := time.Unix(0, clusterTSStart).Format(time.RFC3339Nano)

	// A previous version of the code did a SELECT on system.descriptor. This
	// required the SELECT privilege to the descriptor table, which only root
	// has. Allowing non-root to do this would let users see other users' table
	// descriptors which is a problem in multi-tenancy.

	// Fetch column types.
	rows, err := conn.Query(fmt.Sprintf("SHOW COLUMNS FROM %s", tablename), nil)
	if err != nil {
		return err
	}
	vals = make([]driver.Value, 2)
	coltypes := make(map[string]string)
	for {
		if err := rows.Next(vals); err == io.EOF {
			break
		} else if err != nil {
			return err
		}
		name, ok := vals[0].(string)
		if !ok {
			return fmt.Errorf("unexpected value: %T", vals[1])

		}
		typ, ok := vals[1].(string)
		if !ok {
			return fmt.Errorf("unexpected value: %T", vals[4])

		}
		coltypes[name] = typ
	}
	if err := rows.Close(); err != nil {
		return err
	}

	// index holds the names, in order, of the primary key columns.
	var index []string
	// Primary index is always the first index returned by SHOW INDEX.
	rows, err = conn.Query(fmt.Sprintf("SHOW INDEX FROM %s", tablename), nil)
	if err != nil {
		return err
	}
	vals = make([]driver.Value, 5)
	var primaryIndex string
	// Find the primary index columns.
	for {
		if err := rows.Next(vals); err == io.EOF {
			break
		} else if err != nil {
			return err
		}
		b, ok := vals[1].(string)
		if !ok {
			return fmt.Errorf("unexpected value: %T", vals[1])
		}
		if primaryIndex == "" {
			primaryIndex = b
		} else if primaryIndex != b {
			break
		}
		b, ok = vals[4].(string)
		if !ok {
			return fmt.Errorf("unexpected value: %T", vals[4])
		}
		index = append(index, parser.Name(b).String())
	}
	if err := rows.Close(); err != nil {
		return err
	}
	if len(index) == 0 {
		return fmt.Errorf("no primary key index found")
	}
	indexes := strings.Join(index, ", ")

	// Build the SELECT query.
	var sbuf bytes.Buffer
	fmt.Fprintf(&sbuf, "SELECT %s, * FROM %s@%s AS OF SYSTEM TIME '%s'", indexes, tablename, primaryIndex, clusterTS)

	var wbuf bytes.Buffer
	fmt.Fprintf(&wbuf, " WHERE ROW (%s) > ROW (", indexes)
	for i := range index {
		if i > 0 {
			wbuf.WriteString(", ")
		}
		fmt.Fprintf(&wbuf, "$%d", i+1)
	}
	wbuf.WriteString(")")
	// No WHERE clause first time, so add a place to inject it.
	fmt.Fprintf(&sbuf, "%%s ORDER BY %s LIMIT %d", indexes, limit)
	bs := sbuf.String()

	vals, err = conn.QueryRow(fmt.Sprintf("SHOW CREATE TABLE %s", tablename), nil)
	if err != nil {
		return err
	}
	create := vals[1].(string)
	if _, err := w.Write([]byte(create)); err != nil {
		return err
	}
	if _, err := w.Write([]byte(";\n")); err != nil {
		return err
	}

	if err := conn.Exec("COMMIT", nil); err != nil {
		return err
	}

	// pk holds the last values of the fetched primary keys
	var pk []driver.Value
	q := fmt.Sprintf(bs, "")
	for {
		rows, err := conn.Query(q, pk)
		if err != nil {
			return err
		}
		cols := rows.Columns()
		pkcols := cols[:len(index)]
		cols = cols[len(index):]
		inserts := make([][]string, 0, limit)
		i := 0
		for i < limit {
			vals := make([]driver.Value, len(cols)+len(pkcols))
			if err := rows.Next(vals); err == io.EOF {
				break
			} else if err != nil {
				return err
			}
			if pk == nil {
				q = fmt.Sprintf(bs, wbuf.String())
			}
			pk = vals[:len(index)]
			vals = vals[len(index):]
			ivals := make([]string, len(vals))
			// Values need to be correctly encoded for INSERT statements in a text file.
			for si, sv := range vals {
				switch t := sv.(type) {
				case nil:
					ivals[si] = "NULL"
				case bool:
					ivals[si] = parser.MakeDBool(parser.DBool(t)).String()
				case int64:
					ivals[si] = parser.NewDInt(parser.DInt(t)).String()
				case float64:
					ivals[si] = parser.NewDFloat(parser.DFloat(t)).String()
				case string:
					ivals[si] = parser.NewDString(t).String()
				case []byte:
					switch ct := coltypes[cols[si]]; ct {
					case "INTERVAL":
						ivals[si] = fmt.Sprintf("'%s'", t)
					case "BYTES":
						ivals[si] = parser.NewDBytes(parser.DBytes(t)).String()
					default:
						// STRING and DECIMAL types can have optional length
						// suffixes, so only examine the prefix of the type.
						if strings.HasPrefix(coltypes[cols[si]], "STRING") {
							ivals[si] = parser.NewDString(string(t)).String()
						} else if strings.HasPrefix(coltypes[cols[si]], "DECIMAL") {
							ivals[si] = string(t)
						} else {
							panic(errors.Errorf("unknown []byte type: %s, %v: %s", t, cols[si], coltypes[cols[si]]))
						}
					}
				case time.Time:
					var d parser.Datum
					ct := coltypes[cols[si]]
					switch ct {
					case "DATE":
						d = parser.NewDDateFromTime(t, time.UTC)
					case "TIMESTAMP":
						d = parser.MakeDTimestamp(t, time.Nanosecond)
					case "TIMESTAMP WITH TIME ZONE":
						d = parser.MakeDTimestampTZ(t, time.Nanosecond)
					default:
						panic(errors.Errorf("unknown timestamp type: %s, %v: %s", t, cols[si], coltypes[cols[si]]))
					}
					ivals[si] = fmt.Sprintf("'%s'", d)
				default:
					panic(errors.Errorf("unknown field type: %T (%s)", t, cols[si]))
				}
			}
			inserts = append(inserts, ivals)
			i++
		}
		for si, sv := range pk {
			b, ok := sv.([]byte)
			if ok && strings.HasPrefix(coltypes[pkcols[si]], "STRING") {
				// Primary key strings need to be converted to a go string, but not SQL
				// encoded since they aren't being written to a text file.
				pk[si] = string(b)
			}
		}
		if err := rows.Close(); err != nil {
			return err
		}
		if i == 0 {
			break
		}
		fmt.Fprintf(w, "\nINSERT INTO %s VALUES", tablename)
		for idx, values := range inserts {
			if idx > 0 {
				fmt.Fprint(w, ",")
			}
			fmt.Fprint(w, "\n\t(")
			for vi, v := range values {
				if vi > 0 {
					fmt.Fprint(w, ", ")
				}
				fmt.Fprint(w, v)
			}
			fmt.Fprint(w, ")")
		}
		fmt.Fprintln(w, ";")
		if i < limit {
			break
		}
	}
	return nil
}