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
