SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 4)
    Identifier t1.a (alias t1_a)
    Identifier t2.a (alias t2_a)
    Identifier t2.b (alias t2_b)
    Identifier t3.b (alias t3_b)
   TablesInSelectQuery (children 3)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier table1 (alias t1)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier table2 (alias t2)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier t1.a
        Identifier t2.a
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier table3 (alias t3)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier t2.b
        Identifier t3.b
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier t1.a
