// SanitizeVarFreeExpr verifies a default expression is valid, has the
// correct type and contains no variable expressions.
func SanitizeVarFreeExpr(expr parser.Expr, expectedType parser.Type, context string) error {
if parser.ContainsVars(expr) {
return exprContainsVarsError(context, expr)
}
typedExpr, err := parser.TypeCheck(expr, nil, expectedType)
if err != nil {
return err
}
if defaultType := typedExpr.ResolvedType(); !expectedType.Equal(defaultType) {
return incompatibleExprTypeError(context, expectedType, defaultType)
}
return nil
}
func (p *planner) SetTimeZone(n *parser.SetTimeZone) (planNode, error) {
typedValue, err := parser.TypeCheck(n.Value, nil, parser.TypeInt)
if err != nil {
return nil, err
}
d, err := typedValue.Eval(&p.evalCtx)
if err != nil {
return nil, err
}
var loc *time.Location
var offset int64
switch v := d.(type) {
case *parser.DString:
location := string(*v)
loc, err = timeutil.LoadLocation(location)
if err != nil {
return nil, fmt.Errorf("cannot find time zone %q: %v", location, err)
}
case *parser.DInterval:
offset, _, _, err = v.Duration.Div(time.Second.Nanoseconds()).Encode()
if err != nil {
return nil, err
}
case *parser.DInt:
offset = int64(*v) * 60 * 60
case *parser.DFloat:
offset = int64(float64(*v) * 60.0 * 60.0)
case *parser.DDecimal:
sixty := inf.NewDec(60, 0)
sixty.Mul(sixty, sixty).Mul(sixty, &v.Dec)
sixty.Round(sixty, 0, inf.RoundDown)
var ok bool
if offset, ok = sixty.Unscaled(); !ok {
return nil, fmt.Errorf("time zone value %s would overflow an int64", sixty)
}
default:
return nil, fmt.Errorf("bad time zone value: %v", n.Value)
}
if loc == nil {
loc = time.FixedZone(d.String(), int(offset))
}
p.session.Location = loc
return &emptyNode{}, nil
}
func makeDefaultExprs(
cols []sqlbase.ColumnDescriptor, parse *parser.Parser, evalCtx *parser.EvalContext,
) ([]parser.TypedExpr, error) {
// Check to see if any of the columns have DEFAULT expressions. If there
// are no DEFAULT expressions, we don't bother with constructing the
// defaults map as the defaults are all NULL.
haveDefaults := false
for _, col := range cols {
if col.DefaultExpr != nil {
haveDefaults = true
break
}
}
if !haveDefaults {
return nil, nil
}
// Build the default expressions map from the parsed SELECT statement.
defaultExprs := make([]parser.TypedExpr, 0, len(cols))
exprStrings := make([]string, 0, len(cols))
for _, col := range cols {
if col.DefaultExpr != nil {
exprStrings = append(exprStrings, *col.DefaultExpr)
}
}
exprs, err := parser.ParseExprsTraditional(exprStrings)
if err != nil {
return nil, err
}
defExprIdx := 0
for _, col := range cols {
if col.DefaultExpr == nil {
defaultExprs = append(defaultExprs, parser.DNull)
continue
}
expr := exprs[defExprIdx]
typedExpr, err := parser.TypeCheck(expr, nil, col.Type.ToDatumType())
if err != nil {
return nil, err
}
if typedExpr, err = parse.NormalizeExpr(evalCtx, typedExpr); err != nil {
return nil, err
}
defaultExprs = append(defaultExprs, typedExpr)
defExprIdx++
}
return defaultExprs, nil
}
// analyzeExpr performs semantic analysis of an axpression, including:
// - replacing sub-queries by a sql.subquery node;
// - resolving names (optional);
// - type checking (with optional type enforcement);
// - normalization.
// The parameters sources and IndexedVars, if both are non-nil, indicate
// name resolution should be performed. The IndexedVars map will be filled
// as a result.
func (p *planner) analyzeExpr(
raw parser.Expr,
sources multiSourceInfo,
ivarHelper parser.IndexedVarHelper,
expectedType parser.Type,
requireType bool,
typingContext string,
) (parser.TypedExpr, error) {
// Replace the sub-queries.
// In all contexts that analyze a single expression, a single value
// is expected. Tell this to replaceSubqueries. (See UPDATE for a
// counter-example; cases where a subquery is an operand of a
// comparison are handled specially in the subqueryVisitor already.)
replaced, err := p.replaceSubqueries(raw, 1 /* one value expected */)
if err != nil {
return nil, err
}
// Perform optional name resolution.
var resolved parser.Expr
if sources == nil {
resolved = replaced
} else {
resolved, err = p.resolveNames(replaced, sources, ivarHelper)
if err != nil {
return nil, err
}
}
// Type check.
var typedExpr parser.TypedExpr
if requireType {
typedExpr, err = parser.TypeCheckAndRequire(resolved, &p.semaCtx,
expectedType, typingContext)
} else {
typedExpr, err = parser.TypeCheck(resolved, &p.semaCtx, expectedType)
}
if err != nil {
return nil, err
}
// Normalize.
return p.parser.NormalizeExpr(&p.evalCtx, typedExpr)
}
func parseAndNormalizeExpr(t *testing.T, sql string, sel *selectNode) parser.TypedExpr {
expr, err := parser.ParseExprTraditional(sql)
if err != nil {
t.Fatalf("%s: %v", sql, err)
}
// Perform name resolution because {analyze,simplify}Expr want
// expressions containing IndexedVars.
if expr, err = sel.resolveNames(expr); err != nil {
t.Fatalf("%s: %v", sql, err)
}
typedExpr, err := parser.TypeCheck(expr, nil, parser.NoTypePreference)
if err != nil {
t.Fatalf("%s: %v", sql, err)
}
ctx := &parser.EvalContext{}
if typedExpr, err = ctx.NormalizeExpr(typedExpr); err != nil {
t.Fatalf("%s: %v", sql, err)
}
return typedExpr
}
// processExpression parses the string expression inside an Expression,
// interpreting $0, $1, etc as indexed variables.
func processExpression(exprSpec Expression, h *parser.IndexedVarHelper) (parser.TypedExpr, error) {
if exprSpec.Expr == "" {
return nil, nil
}
expr, err := parser.ParseExprTraditional(exprSpec.Expr)
if err != nil {
return nil, err
}
// Convert Placeholders to IndexedVars
v := valArgsConvert{h: h, err: nil}
expr, _ = parser.WalkExpr(&v, expr)
if v.err != nil {
return nil, v.err
}
// Convert to a fully typed expression.
typedExpr, err := parser.TypeCheck(expr, nil, parser.NoTypePreference)
if err != nil {
return nil, err
}
return typedExpr, nil
}
// processExpression parses the string expression inside an Expression,
// and associates ordinal references (@1, @2, etc) with the given helper.
func processExpression(exprSpec Expression, h *parser.IndexedVarHelper) (parser.TypedExpr, error) {
if exprSpec.Expr == "" {
return nil, nil
}
expr, err := parser.ParseExprTraditional(exprSpec.Expr)
if err != nil {
return nil, err
}
// Bind IndexedVars to our eh.vars.
v := ivarBinder{h: h, err: nil}
parser.WalkExprConst(&v, expr)
if v.err != nil {
return nil, v.err
}
// Convert to a fully typed expression.
typedExpr, err := parser.TypeCheck(expr, nil, parser.NoTypePreference)
if err != nil {
return nil, err
}
return typedExpr, nil
}
// Update updates columns for a selection of rows from a table.
// Privileges: UPDATE and SELECT on table. We currently always use a select statement.
// Notes: postgres requires UPDATE. Requires SELECT with WHERE clause with table.
// mysql requires UPDATE. Also requires SELECT with WHERE clause with table.
// TODO(guanqun): need to support CHECK in UPDATE
func (p *planner) Update(
n *parser.Update, desiredTypes []parser.Type, autoCommit bool,
) (planNode, error) {
tracing.AnnotateTrace()
tn, err := p.getAliasedTableName(n.Table)
if err != nil {
return nil, err
}
en, err := p.makeEditNode(tn, autoCommit, privilege.UPDATE)
if err != nil {
return nil, err
}
exprs := make([]*parser.UpdateExpr, len(n.Exprs))
for i, expr := range n.Exprs {
// Replace the sub-query nodes.
newExpr, err := p.replaceSubqueries(expr.Expr, len(expr.Names))
if err != nil {
return nil, err
}
exprs[i] = &parser.UpdateExpr{Tuple: expr.Tuple, Expr: newExpr, Names: expr.Names}
}
// Determine which columns we're inserting into.
names, err := p.namesForExprs(exprs)
if err != nil {
return nil, err
}
updateCols, err := p.processColumns(en.tableDesc, names)
if err != nil {
return nil, err
}
defaultExprs, err := makeDefaultExprs(updateCols, &p.parser, &p.evalCtx)
if err != nil {
return nil, err
}
var requestedCols []sqlbase.ColumnDescriptor
if len(n.Returning) > 0 || len(en.tableDesc.Checks) > 0 {
// TODO(dan): This could be made tighter, just the rows needed for RETURNING
// exprs.
requestedCols = en.tableDesc.Columns
}
fkTables := tablesNeededForFKs(*en.tableDesc, CheckUpdates)
if err := p.fillFKTableMap(fkTables); err != nil {
return nil, err
}
ru, err := makeRowUpdater(p.txn, en.tableDesc, fkTables, updateCols, requestedCols, rowUpdaterDefault)
if err != nil {
return nil, err
}
tw := tableUpdater{ru: ru, autoCommit: autoCommit}
tracing.AnnotateTrace()
// Generate the list of select targets. We need to select all of the columns
// plus we select all of the update expressions in case those expressions
// reference columns (e.g. "UPDATE t SET v = v + 1"). Note that we flatten
// expressions for tuple assignments just as we flattened the column names
// above. So "UPDATE t SET (a, b) = (1, 2)" translates into select targets of
// "*, 1, 2", not "*, (1, 2)".
targets := sqlbase.ColumnsSelectors(ru.fetchCols)
i := 0
// Remember the index where the targets for exprs start.
exprTargetIdx := len(targets)
desiredTypesFromSelect := make([]parser.Type, len(targets), len(targets)+len(exprs))
for i := range targets {
desiredTypesFromSelect[i] = parser.TypeAny
}
for _, expr := range exprs {
if expr.Tuple {
switch t := expr.Expr.(type) {
case (*parser.Tuple):
for _, e := range t.Exprs {
typ := updateCols[i].Type.ToDatumType()
e := fillDefault(e, typ, i, defaultExprs)
targets = append(targets, parser.SelectExpr{Expr: e})
desiredTypesFromSelect = append(desiredTypesFromSelect, typ)
i++
}
default:
return nil, fmt.Errorf("cannot use this expression to assign multiple columns: %s", expr.Expr)
}
} else {
typ := updateCols[i].Type.ToDatumType()
e := fillDefault(expr.Expr, typ, i, defaultExprs)
targets = append(targets, parser.SelectExpr{Expr: e})
desiredTypesFromSelect = append(desiredTypesFromSelect, typ)
i++
}
}
rows, err := p.SelectClause(&parser.SelectClause{
Exprs: targets,
From: &parser.From{Tables: []parser.TableExpr{n.Table}},
Where: n.Where,
}, nil, nil, desiredTypesFromSelect, publicAndNonPublicColumns)
if err != nil {
return nil, err
}
// Placeholders have their types populated in the above Select if they are part
// of an expression ("SET a = 2 + $1") in the type check step where those
// types are inferred. For the simpler case ("SET a = $1"), populate them
// using checkColumnType. This step also verifies that the expression
// types match the column types.
sel := rows.(*selectTopNode).source.(*selectNode)
for i, target := range sel.render[exprTargetIdx:] {
// DefaultVal doesn't implement TypeCheck
if _, ok := target.(parser.DefaultVal); ok {
continue
}
// TODO(nvanbenschoten) isn't this TypeCheck redundant with the call to SelectClause?
typedTarget, err := parser.TypeCheck(target, &p.semaCtx, updateCols[i].Type.ToDatumType())
if err != nil {
return nil, err
}
err = sqlbase.CheckColumnType(updateCols[i], typedTarget.ResolvedType(), p.semaCtx.Placeholders)
if err != nil {
return nil, err
}
}
updateColsIdx := make(map[sqlbase.ColumnID]int, len(ru.updateCols))
for i, col := range ru.updateCols {
updateColsIdx[col.ID] = i
}
un := &updateNode{
n: n,
editNodeBase: en,
updateCols: ru.updateCols,
updateColsIdx: updateColsIdx,
tw: tw,
}
if err := un.checkHelper.init(p, tn, en.tableDesc); err != nil {
return nil, err
}
if err := un.run.initEditNode(&un.editNodeBase, rows, n.Returning, desiredTypes); err != nil {
return nil, err
}
return un, nil
}
// Set sets session variables.
// Privileges: None.
// Notes: postgres/mysql do not require privileges for session variables (some exceptions).
func (p *planner) Set(n *parser.Set) (planNode, error) {
if n.Name == nil {
// A client has sent the reserved internal syntax SET ROW ...
// Reject it.
return nil, errors.New("invalid statement: SET ROW")
}
// By using VarName.String() here any variables that are keywords will
// be double quoted.
name := strings.ToUpper(n.Name.String())
typedValues := make([]parser.TypedExpr, len(n.Values))
for i, expr := range n.Values {
typedValue, err := parser.TypeCheck(expr, nil, parser.TypeString)
if err != nil {
return nil, err
}
typedValues[i] = typedValue
}
switch name {
case `DATABASE`:
dbName, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
if len(dbName) != 0 {
// Verify database descriptor exists.
if _, err := p.mustGetDatabaseDesc(dbName); err != nil {
return nil, err
}
}
p.session.Database = dbName
p.evalCtx.Database = dbName
case `SYNTAX`:
s, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
switch parser.Name(s).Normalize() {
case parser.ReNormalizeName(parser.Modern.String()):
p.session.Syntax = int32(parser.Modern)
case parser.ReNormalizeName(parser.Traditional.String()):
p.session.Syntax = int32(parser.Traditional)
default:
return nil, fmt.Errorf("%s: \"%s\" is not in (%q, %q)", name, s, parser.Modern, parser.Traditional)
}
case `EXTRA_FLOAT_DIGITS`:
// These settings are sent by the JDBC driver but we silently ignore them.
case `APPLICATION_NAME`:
// These settings are sent by the clients to improve query logging on the server,
// but we silently ignore them.
case `DEFAULT_TRANSACTION_ISOLATION`:
// It's unfortunate that clients want us to support both SET
// SESSION CHARACTERISTICS AS TRANSACTION ..., which takes the
// isolation level as keywords/identifiers (e.g. JDBC), and SET
// DEFAULT_TRANSACTION_ISOLATION TO '...', which takes an
// expression (e.g. psycopg2). But that's how it is. Just ensure
// this code keeps in sync with SetDefaultIsolation() below.
s, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
switch strings.ToUpper(s) {
case `READ UNCOMMITTED`, `READ COMMITTED`, `SNAPSHOT`:
p.session.DefaultIsolationLevel = enginepb.SNAPSHOT
case `REPEATABLE READ`, `SERIALIZABLE`:
p.session.DefaultIsolationLevel = enginepb.SERIALIZABLE
default:
return nil, fmt.Errorf("%s: unknown isolation level: %q", name, s)
}
case `DIST_SQL`:
s, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
switch parser.Name(s).Normalize() {
case parser.ReNormalizeName("sync"):
p.session.DistSQLMode = distSQLSync
case parser.ReNormalizeName("async"):
p.session.DistSQLMode = distSQLAsync
default:
return nil, fmt.Errorf("%s: \"%s\" not supported", name, s)
}
default:
return nil, fmt.Errorf("unknown variable: %q", name)
}
return &emptyNode{}, nil
}
// Set sets session variables.
// Privileges: None.
// Notes: postgres/mysql do not require privileges for session variables (some exceptions).
func (p *planner) Set(n *parser.Set) (planNode, error) {
if n.Name == nil {
// A client has sent the reserved internal syntax SET ROW ...
// Reject it.
return nil, errors.New("invalid statement: SET ROW")
}
// By using VarName.String() here any variables that are keywords will
// be double quoted.
name := strings.ToUpper(n.Name.String())
typedValues := make([]parser.TypedExpr, len(n.Values))
for i, expr := range n.Values {
typedValue, err := parser.TypeCheck(expr, nil, parser.TypeString)
if err != nil {
return nil, err
}
typedValues[i] = typedValue
}
switch name {
case `DATABASE`:
dbName, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
if len(dbName) != 0 {
// Verify database descriptor exists.
if _, err := p.mustGetDatabaseDesc(dbName); err != nil {
return nil, err
}
}
p.session.Database = dbName
p.evalCtx.Database = dbName
case `SYNTAX`:
s, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
switch parser.Name(s).Normalize() {
case parser.ReNormalizeName(parser.Modern.String()):
p.session.Syntax = int32(parser.Modern)
case parser.ReNormalizeName(parser.Traditional.String()):
p.session.Syntax = int32(parser.Traditional)
default:
return nil, fmt.Errorf("%s: \"%s\" is not in (%q, %q)", name, s, parser.Modern, parser.Traditional)
}
case `DEFAULT_TRANSACTION_ISOLATION`:
// It's unfortunate that clients want us to support both SET
// SESSION CHARACTERISTICS AS TRANSACTION ..., which takes the
// isolation level as keywords/identifiers (e.g. JDBC), and SET
// DEFAULT_TRANSACTION_ISOLATION TO '...', which takes an
// expression (e.g. psycopg2). But that's how it is. Just ensure
// this code keeps in sync with SetDefaultIsolation() below.
s, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
switch strings.ToUpper(s) {
case `READ UNCOMMITTED`, `READ COMMITTED`, `SNAPSHOT`:
p.session.DefaultIsolationLevel = enginepb.SNAPSHOT
case `REPEATABLE READ`, `SERIALIZABLE`:
p.session.DefaultIsolationLevel = enginepb.SERIALIZABLE
default:
return nil, fmt.Errorf("%s: unknown isolation level: %q", name, s)
}
case `DIST_SQL`:
s, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
switch parser.Name(s).Normalize() {
case parser.ReNormalizeName("off"):
p.session.DistSQLMode = distSQLOff
case parser.ReNormalizeName("on"):
p.session.DistSQLMode = distSQLOn
case parser.ReNormalizeName("always"):
p.session.DistSQLMode = distSQLAlways
default:
return nil, fmt.Errorf("%s: \"%s\" not supported", name, s)
}
// These settings are sent by various client drivers. We don't support
// changing them, so we either silently ignore them or throw an error given
// a setting that we do not respect.
case `EXTRA_FLOAT_DIGITS`:
// See https://www.postgresql.org/docs/9.6/static/runtime-config-client.html
case `APPLICATION_NAME`:
// Set by clients to improve query logging.
// See https://www.postgresql.org/docs/9.6/static/runtime-config-logging.html#GUC-APPLICATION-NAME
case `CLIENT_ENCODING`:
// See https://www.postgresql.org/docs/9.6/static/multibyte.html
s, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
if strings.ToUpper(s) != "UTF8" {
return nil, fmt.Errorf("non-UTF8 encoding %s not supported", s)
}
case `SEARCH_PATH`:
// Controls the schema search order. We don't really support this as we
// don't have first-class support for schemas.
// TODO(jordan) can we hook this up to EvalContext.SearchPath without
// breaking things?
// See https://www.postgresql.org/docs/9.6/static/runtime-config-client.html
case `STANDARD_CONFORMING_STRINGS`:
// If true, escape backslash literals in strings. We do this by default,
// and we do not support the opposite behavior.
// See https://www.postgresql.org/docs/9.1/static/runtime-config-compatible.html#GUC-STANDARD-CONFORMING-STRINGS
s, err := p.getStringVal(name, typedValues)
if err != nil {
return nil, err
}
if parser.Name(s).Normalize() != parser.ReNormalizeName("on") {
return nil, fmt.Errorf("%s: \"%s\" not supported", name, s)
}
case `CLIENT_MIN_MESSAGES`:
// Controls returned message verbosity. We don't support this.
// See https://www.postgresql.org/docs/9.6/static/runtime-config-compatible.html
default:
return nil, fmt.Errorf("unknown variable: %q", name)
}
return &emptyNode{}, nil
}
