Exemplo n.º 1
0
// MakeColumnDefDescs creates the column descriptor for a column, as well as the
// index descriptor if the column is a primary key or unique.
func MakeColumnDefDescs(d *parser.ColumnTableDef) (*ColumnDescriptor, *IndexDescriptor, error) {
	col := &ColumnDescriptor{
		Name:     string(d.Name),
		Nullable: d.Nullable.Nullability != parser.NotNull && !d.PrimaryKey,
	}

	if d.Nullable.ConstraintName != "" {
		col.NullableConstraintName = string(d.Nullable.ConstraintName)
	}

	var colDatumType parser.Datum
	switch t := d.Type.(type) {
	case *parser.BoolColType:
		col.Type.Kind = ColumnType_BOOL
		colDatumType = parser.TypeBool
	case *parser.IntColType:
		col.Type.Kind = ColumnType_INT
		col.Type.Width = int32(t.N)
		colDatumType = parser.TypeInt
		if t.IsSerial() {
			if d.DefaultExpr.Expr != nil {
				return nil, nil, fmt.Errorf("SERIAL column %q cannot have a default value", col.Name)
			}
			s := "unique_rowid()"
			col.DefaultExpr = &s
		}
	case *parser.FloatColType:
		col.Type.Kind = ColumnType_FLOAT
		col.Type.Precision = int32(t.Prec)
		colDatumType = parser.TypeFloat
	case *parser.DecimalColType:
		col.Type.Kind = ColumnType_DECIMAL
		col.Type.Width = int32(t.Scale)
		col.Type.Precision = int32(t.Prec)
		colDatumType = parser.TypeDecimal
	case *parser.DateColType:
		col.Type.Kind = ColumnType_DATE
		colDatumType = parser.TypeDate
	case *parser.TimestampColType:
		col.Type.Kind = ColumnType_TIMESTAMP
		colDatumType = parser.TypeTimestamp
	case *parser.TimestampTZColType:
		col.Type.Kind = ColumnType_TIMESTAMPTZ
		colDatumType = parser.TypeTimestampTZ
	case *parser.IntervalColType:
		col.Type.Kind = ColumnType_INTERVAL
		colDatumType = parser.TypeInterval
	case *parser.StringColType:
		col.Type.Kind = ColumnType_STRING
		col.Type.Width = int32(t.N)
		colDatumType = parser.TypeString
	case *parser.BytesColType:
		col.Type.Kind = ColumnType_BYTES
		colDatumType = parser.TypeBytes
	default:
		return nil, nil, errors.Errorf("unexpected type %T", t)
	}

	if col.Type.Kind == ColumnType_DECIMAL {
		switch {
		case col.Type.Precision == 0 && col.Type.Width > 0:
			// TODO (seif): Find right range for error message.
			return nil, nil, errors.New("invalid NUMERIC precision 0")
		case col.Type.Precision < col.Type.Width:
			return nil, nil, fmt.Errorf("NUMERIC scale %d must be between 0 and precision %d",
				col.Type.Width, col.Type.Precision)
		}
	}

	if d.DefaultExpr.Expr != nil {
		// Verify the default expression type is compatible with the column type.
		if err := SanitizeVarFreeExpr(d.DefaultExpr.Expr, colDatumType, "DEFAULT"); err != nil {
			return nil, nil, err
		}
		var p parser.Parser
		if p.AggregateInExpr(d.DefaultExpr.Expr) {
			return nil, nil, fmt.Errorf("Aggregate functions are not allowed in DEFAULT expressions")
		}
		if d.DefaultExpr.ConstraintName != "" {
			col.DefaultExprConstraintName = string(d.DefaultExpr.ConstraintName)
		}
		s := d.DefaultExpr.Expr.String()
		col.DefaultExpr = &s
	}

	var idx *IndexDescriptor
	if d.PrimaryKey || d.Unique {
		idx = &IndexDescriptor{
			Unique:           true,
			ColumnNames:      []string{string(d.Name)},
			ColumnDirections: []IndexDescriptor_Direction{IndexDescriptor_ASC},
		}
		if d.UniqueConstraintName != "" {
			idx.Name = string(d.UniqueConstraintName)
		}
	}

	return col, idx, nil
}