inserting unique value

I need to insert a unique value into a (not auto-increment) column.
I try

insert into idtest (val) values ((select max(val) from idtest)+1);

but I get

ERROR 1093 (HY000): You can't specify target table 'idtest' for update
in FROM clause

- what is the correct way to do this?

Regards,
Rune

== Quote from Rune Zedeler (rz@daimi.au.dk)'s article
> I need to insert a unique value into a (not auto-increment) column.
> I try
> insert into idtest (val) values ((select max(val) from idtest)+1);
> but I get
> ERROR 1093 (HY000): You can't specify target table 'idtest' for update
> in FROM clause
> - what is the correct way to do this?
> Regards,
> Rune

how about this:

insert into idtest (val) (select (max(val)+1) from idtest);

let me know if it works for you.
--
POST BY: lark with PHP News Reader