Re: Problem Query EXISTS and IN

[Michael Stassen]

[EMAIL PROTECTED] wrote:
Hi

(Sorry by my english, i speak spanish)

I have problem with a Query.

It does not recognize EXISTS nor IN nor NOT IN

My version is MySQL 4.0.11a-gamma

But I do not know if it recognizes those clauses.

I have dealed with the two forms:

1.  SELECT usu_id FROM usuario WHERE NOT EXISTS (SELECT * FROM grupo WHERE
usuario.g_id=grupo.g_id AND grupo.g_id > 5)
2.  SELECT usu_id FROM usuario WHERE g_id NOT IN (SELECT g_id FROM grupo WHERE
grupo.g_id > 5)
Thanks by your help.

Juan
MySQL understands IN and NOT IN.  The problem is that you need at least 
mysql 4.1.x for subqueries, and thus for EXISTS.  You can, however, rewrite 
your queries to use a JOIN instead of a subquery -- something like this:

  SELECT usu_id
  FROM usuario
  LEFT JOIN grupo
  ON usuario.g_id=grupo.g_id AND grupo.g_id > 5
  WHERE grupo.g_id IS NULL;
See the manual for more

  <http://www.mysql.com/doc/en/Rewriting_subqueries.html>

Michael

P.S.  No need to apologize -- your English is much better than my Spanish.

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