Re: join table with empty fields and default

Thank you for your post. To make things a little bit complicated:

Suppose I have another table UserInformation

UserInfomation
{
    userid integer referenes user(id),
     mothername text
}

I would like methername also appear in the final join. Suppose each
user must have a mothername.

Could you please whow me the sql again?

Thanks again,

qq



Michael Fuhr wrote:
> On Sat, Jul 22, 2006 at 12:47:42PM -0700, quickcur@yahoo.com wrote:
> > I would like to join table user and userwork, where if a user has a
> > work, I list it. If he does not, I give it some default value "no work"
>
> You could use an outer join and COALESCE.
>
> http://www.postgresql.org/docs/8.1/interactive/tutorial-join.html
> http://www.postgresql.org/docs/8.1/interactive/queries-table-expressions.html#QUERIES-JOIN
> http://www.postgresql.org/docs/8.1/interactive/functions-conditional.html#AEN12639
>
> Example:
>
> SELECT u.id, u.name, u.address, COALESCE(uw.work, 'no work') AS work
> FROM "user" AS u
> LEFT OUTER JOIN userwork AS uw ON uw.userid = u.id;
>
> --
> Michael Fuhr
>
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