SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Identifier ID
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier m
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier b
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier key
   ExpressionList (children 1)
    Identifier ID
