Method parseWindowFrame

pkg/sql/parser/window.go:471–510

parseWindowFrame parses a window frame clause

(frameType string)

// parseWindowFrame parses a window frame clause
func (p *Parser) parseWindowFrame(frameType string) (*ast.WindowFrame, error) {
	frame := &ast.WindowFrame{
		Type: frameType,
	}

	// Parse frame bounds
	if p.isType(models.TokenTypeBetween) {
		p.advance() // Consume BETWEEN

		// Parse start bound
		startBound, err := p.parseFrameBound()
		if err != nil {
			return nil, err
		}
		frame.Start = *startBound

		// Expect AND
		if !p.isType(models.TokenTypeAnd) {
			return nil, p.expectedError("AND")
		}
		p.advance() // Consume AND

		// Parse end bound
		endBound, err := p.parseFrameBound()
		if err != nil {
			return nil, err
		}
		frame.End = endBound
	} else {
		// Single bound (implies CURRENT ROW as end)
		startBound, err := p.parseFrameBound()
		if err != nil {
			return nil, err
		}
		frame.Start = *startBound
		// End is nil for single bound
	}

	return frame, nil
}

// parseFrameBound parses a window frame bound
func (p *Parser) parseFrameBound() (*ast.WindowFrameBound, error) {