Method parseFetchClause

pkg/sql/parser/select_clauses.go:675–731

parseFetchClause parses the SQL-99 FETCH FIRST/NEXT clause (F861, F862). Syntax: FETCH {FIRST | NEXT} n [{ROW | ROWS}] [{PERCENT}] {ONLY | WITH TIES} Examples: FETCH FIRST 5 ROWS ONLY FETCH NEXT 10 ROWS ONLY FETCH FIRST 10 PERCENT ROWS WITH TIES FETCH NEXT 20 ROWS WITH TIES

()

//	FETCH FIRST 10 PERCENT ROWS WITH TIES
//	FETCH NEXT 20 ROWS WITH TIES
func (p *Parser) parseFetchClause() (*ast.FetchClause, error) {
	fetchClause := &ast.FetchClause{}

	// Consume FETCH keyword (already checked by caller)
	p.advance()

	// Parse FIRST or NEXT
	if p.isType(models.TokenTypeFirst) {
		fetchClause.FetchType = "FIRST"
		p.advance()
	} else if p.isType(models.TokenTypeNext) {
		fetchClause.FetchType = "NEXT"
		p.advance()
	} else {
		return nil, p.expectedError("FIRST or NEXT after FETCH")
	}

	// Parse the count value
	if !p.isNumericLiteral() {
		return nil, p.expectedError("integer for FETCH count")
	}

	// Convert string to int64
	var fetchVal int64
	_, _ = fmt.Sscanf(p.currentToken.Token.Value, "%d", &fetchVal)
	fetchClause.FetchValue = &fetchVal
	p.advance()

	// Check for PERCENT (optional)
	if p.isType(models.TokenTypePercent) {
		fetchClause.IsPercent = true
		p.advance()
	}

	// Check for ROW/ROWS (optional)
	if p.isAnyType(models.TokenTypeRow, models.TokenTypeRows) {
		p.advance() // Consume ROW/ROWS
	}

	// Parse ONLY or WITH TIES
	if p.isType(models.TokenTypeOnly) {
		fetchClause.WithTies = false
		p.advance()
	} else if p.isType(models.TokenTypeWith) {
		p.advance() // Consume WITH
		if !p.isType(models.TokenTypeTies) {
			return nil, p.expectedError("TIES after WITH")
		}
		fetchClause.WithTies = true
		p.advance() // Consume TIES
	} else {
		// If neither ONLY nor WITH TIES, default to ONLY behavior
		fetchClause.WithTies = false
	}

	return fetchClause, nil
}