SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Function multiIf (children 1) ExpressionList (children 3) Function equals (children 1) ExpressionList (children 2) Identifier a Literal UInt64_1 Literal UInt64_0 Literal NULL TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier test_00688