SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias t1) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 1)
           Identifier key (alias a)
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             TableIdentifier t1
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias t2) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 1)
           Identifier key (alias c)
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             TableIdentifier t1
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier c
        Identifier a
   Identifier a
