Struct SelectStatement

pkg/sql/ast/ast.go:423–451

SelectStatement represents a SELECT SQL statement with full SQL-99/SQL:2003 support. SelectStatement is the primary query statement type supporting: - CTEs (WITH clause) - DISTINCT and DISTINCT ON (PostgreSQL) - Multiple FROM tables and subqueries - All JOIN types with LATERAL support - WHERE, GROU

//   - Enhanced LATERAL JOIN support via TableReference.Lateral
//   - FILTER clause support via FunctionCall.Filter
type SelectStatement struct {
	With              *WithClause
	Distinct          bool
	DistinctOnColumns []Expression // PostgreSQL DISTINCT ON (expr, ...) clause
	Top               *TopClause   // SQL Server TOP N [PERCENT] clause
	Columns           []Expression
	From              []TableReference
	TableName         string // Added for pool operations
	Joins             []JoinClause
	PrewhereClause    Expression    // ClickHouse PREWHERE clause (applied before WHERE, before reading data)
	Sample            *SampleClause // ClickHouse SAMPLE clause (comes after FROM/FINAL, before PREWHERE)
	Where             Expression
	GroupBy           []Expression
	Having            Expression
	Qualify           Expression // Snowflake / BigQuery QUALIFY clause (filters after window functions)
	// StartWith is the optional seed condition for CONNECT BY (MariaDB 10.2+).
	// Example: START WITH parent_id IS NULL
	StartWith Expression // MariaDB hierarchical query seed
	// ConnectBy holds the hierarchy traversal condition (MariaDB 10.2+).
	// Example: CONNECT BY PRIOR id = parent_id
	ConnectBy *ConnectByClause // MariaDB hierarchical query
	Windows   []WindowSpec
	OrderBy   []OrderByExpression
	Limit     *int
	Offset    *int
	Fetch     *FetchClause    // SQL-99 FETCH FIRST/NEXT clause (F861, F862)
	For       *ForClause      // Row-level locking clause (SQL:2003, PostgreSQL, MySQL)
	Pos       models.Location // Source position of the SELECT keyword (1-based line and column)
}

// TopClause represents SQL Server's TOP N [PERCENT] clause
// Syntax: SELECT TOP n [PERCENT] columns...