>Hi Jim,
>
>>>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"
>>
>
>This will cause a data-type mismatch. If he's testing against the result of the iif(), he's got to use the HAVING clause.

Naw, you don't need a HAVING or a comparison operator, simply

SELECT detail.avr_ari, "J" AS WTG;
FROM general!detail;
WHERE Detail.avr_wtg

will do the trick. Using Detail.avr_wtg = .T. slows things down.