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