Method parseIntervalExpression

pkg/sql/parser/expressions_complex.go:243–270

parseIntervalExpression parses an INTERVAL expression: INTERVAL 'value' Examples: INTERVAL '1 day' INTERVAL '2 hours' INTERVAL '1 year 2 months 3 days' INTERVAL '30 days'

()

//	INTERVAL '1 year 2 months 3 days'
//	INTERVAL '30 days'
func (p *Parser) parseIntervalExpression() (*ast.IntervalExpression, error) {
	// Consume INTERVAL keyword
	p.advance()

	// Support both PostgreSQL style: INTERVAL '1 day'
	// and MySQL style: INTERVAL 30 DAY, INTERVAL 1 HOUR
	if p.isStringLiteral() {
		value := p.currentToken.Token.Value
		p.advance()
		return &ast.IntervalExpression{Value: value}, nil
	}

	// MySQL style: INTERVAL <number> <unit>
	if p.isNumericLiteral() {
		numStr := p.currentToken.Token.Value
		p.advance()
		// Expect a unit keyword (DAY, HOUR, MINUTE, SECOND, MONTH, YEAR, WEEK, etc.)
		unit := strings.ToUpper(p.currentToken.Token.Value)
		p.advance()
		return &ast.IntervalExpression{Value: numStr + " " + unit}, nil
	}

	return nil, goerrors.InvalidSyntaxError(
		"expected string literal or number after INTERVAL keyword",
		p.currentLocation(),
		"Use INTERVAL '1 day' or INTERVAL 1 DAY syntax",
	)
}

// parseArrayConstructor parses PostgreSQL ARRAY constructor syntax.
// Supports both ARRAY[...] (square bracket) and ARRAY(...) (subquery) forms.