Method parseGroupingExpressionList

pkg/sql/parser/grouping.go:27–63

used by ROLLUP and CUBE. Returns error if the list is empty.

(keyword string)

// used by ROLLUP and CUBE. Returns error if the list is empty.
func (p *Parser) parseGroupingExpressionList(keyword string) ([]ast.Expression, error) {
	if !p.isType(models.TokenTypeLParen) {
		return nil, p.expectedError("( after " + keyword)
	}
	p.advance() // Consume (

	// Check for empty list - not allowed for ROLLUP/CUBE
	if p.isType(models.TokenTypeRParen) {
		return nil, goerrors.InvalidSyntaxError(
			keyword+" requires at least one expression",
			p.currentLocation(),
			"",
		)
	}

	// Parse comma-separated expressions
	expressions := make([]ast.Expression, 0)
	for {
		expr, err := p.parseExpression()
		if err != nil {
			return nil, err
		}
		expressions = append(expressions, expr)

		// Check for comma (more expressions) or closing paren
		if p.isType(models.TokenTypeRParen) {
			break
		}
		if !p.isType(models.TokenTypeComma) {
			return nil, p.expectedError(", or ) in " + keyword)
		}
		p.advance() // Consume comma
	}
	p.advance() // Consume )

	return expressions, nil
}

// parseRollup parses ROLLUP(col1, col2, ...) in GROUP BY clause
// ROLLUP generates hierarchical grouping sets from right to left