SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    QualifiedAsterisk (children 1)
     Identifier a1
    QualifiedAsterisk (children 1)
     Identifier a2
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier a1
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier a2
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier a
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier b
