>Dear readers,
>
>When i execute the folowing SQL query, i get the error colomn "WTG"not found.
>
>SELECT detail.avr_ari,;
> iif(Detail.avr_wtg=.t.,'J','N') as WTG;
>FROM general!detail;
>WHERE WTG='J'
>
>Is this an impossible kind of query, to include an expressionalias in the WHERE Clause ?
>
>Any idea's how to solve this ?
>

Bjorn,

The WHERE clause of SELECT si applied to the source tables, there is no fild named WTG in the source fields. You can change it to;

WHERE Detail.avr_wtg = "J"

which will be fast and will work or you can dump the WHERE clause and use;

HAVING WTG="J"

which will be slower but will work.

Having is applied to the result of the query while WHERE is applied to the source tables.