Re: default value returned from sql stmt

Hello

2012/3/30 David Salisbury <salisbury(at)globe(dot)gov>:
>
> In trying to get an sql stmt to return a default value, I read in the docs..
>
> "The COALESCE function returns the first of its arguments that is not null.
> Null is returned only if all arguments are null. It is often used to
> substitute a default value for null values when data is retrieved for
> display, for example:
> SELECT COALESCE(description, short_description, '(none)') ..."
>
> But I seem to be missing something:
>
> development=# create table t1 ( anum integer );
> CREATE TABLE
>
> development=# insert into t1 values ( 2 ), (3);
> INSERT 0 2
>
> development=# select * from t1;
>
>  anum
> ------
>    2
>    3
>
> development=# select  coalesce(anum,100) from t1 where anum = 4;
>  coalesce
> ----------
> (0 rows)

select anum from t1 where anum = 4
union all select 100 limit 1;

Regards

Pavel

>
> Do I have to resort to PLPGSQL for this?
>
> thanks for any info,
>
> -ds
>
> oh.. running 9.1
>
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