SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 4)
    Identifier key1
    Identifier key2
    Identifier key3
    Identifier attr
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t1
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier tj
     TableJoin (children 1)
      ExpressionList (children 3)
       Identifier key3
       Identifier key2
       Identifier key1
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier key1
