Level Extreme platform
Subscription
Corporate profile
Products & Services
Support
Legal
Français
Using a field from derived table in Where issue
Message
 
 
To
All
General information
Forum:
Visual FoxPro
Category:
Other
Title:
Using a field from derived table in Where issue
Environment versions
Visual FoxPro:
VFP 9 SP1
Miscellaneous
Thread ID:
01521189
Message ID:
01521189
Views:
97
Hi,

I can't seem to understand how to deal with the following issue.

I have a SQL Select that uses derived table that creates a column, e.g. TOT_QTY. If there are no records in the LEFT JOIN (derived table) the value set to TOT_QTY is null. So in the SQL Select I use NVL( TOT_QTY, 0 ). And when I look at the resulting query I see that the records from the derived table are included with the value assigned to TOT_QTY as 0. So far so good. But if I include this column name in the WHERE clause (e.g. WHERE TOT_QTY > 0) none of the records are included in the query. It looks like the WHERE always uses the NULL value of the TOT_QTY and not the one that has been "processed" by NVL(). I hope my explanation is clear. What can I do to make the WHERE work in this case? TIA.
"The creative process is nothing but a series of crises." Isaac Bashevis Singer
"My experience is that as soon as people are old enough to know better, they don't know anything at all." Oscar Wilde
"If a nation values anything more than freedom, it will lose its freedom; and the irony of it is that if it is comfort or money that it values more, it will lose that too." W.Somerset Maugham
Next
Reply
Map
View

Click here to load this message in the networking platform