SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 3) ExpressionList (children 4) Identifier product_name Identifier group_name Identifier price Function FIRST_VALUE (alias price_per_group_per_alphab) (children 1) ExpressionList (children 1) Identifier price TablesInSelectQuery (children 2) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier products TablesInSelectQueryElement (children 2) TableExpression (children 1) TableIdentifier product_groups TableJoin (children 1) ExpressionList (children 1) Identifier group_id ExpressionList (children 2) OrderByElement (children 1) Identifier group_name OrderByElement (children 1) Identifier product_name