UPDATE jose INNER JOIN (SELECT First(jose.a) AS a1, Last(jose.a) AS a2, jose.valor, Count(jose.valor) AS CuentaDevalor FROM jose GROUP BY jose.valor HAVING (((Count(jose.valor))>1))) AS j ON jose.valor = j.valor SET jose.ai = j.a1, jose.af = j.a2;

I have an error, the query is not actualizable.

is this sql correct?

That depends. Not for Microsoft SQL Server, but it looks ok at first blush for Jet, the database engine used by Microsoft Access.

Please don't cross post, or at least be up-front about cross-posting if you aren't sure where to post the question.

-PatP

See the Access forum.