SELECT Statement

[garak76]

Hi everybody,

I got a problem with mysql 3.23.56 with windows xp.
I wrote this SQL Statement and it worked fine:

"SELECT COUNT(*) as SchubAnzInGr,
Round((TO_DAYS(NOW()) - TO_DAYS(SichereDiagnose)) / 365)
as ErkDauer
FROM Diagnostik, Schuebe
WHERE Diagnostik.MitgliedsNr = Schuebe.MitgliedsNr
GROUP BY ErkDauer";

But in the next step I have to work with the temporary Fields SchubAnzInGr and ErkDauer like this:

SELECT AVG(SchubAnzInGr) as AVGSchubAnz From ...
Group By ErkDauer

Thanx for any help
Frank

p.s.

Maybe something like :
SELECT AVG(SchubAnzInGr) as AVGSchubAnz FROM (SELECT ...)
Group by ErkDauer???

 

[sleipnir214]

SQL doesn't work that way.

The "AS" clause does not make those columns available to successive queries. It just provides aliases for columns that can be referred-to within the query or by applications processing the return of the query.

If you want those values to be available to successive queries, I recommend that you insert the values into a temporary table.

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http://www.catb.org/~esr/faqs/smart-questions.html

TANSTAAFL!!

 

[garak76]

Yes I know its no longer available, but isnt there
a possibility with cascading SELECT statements like I mentioned in the end of my question ???

If there no way, how do I work with temporary tables,
do you know a good docu ?

 

[sleipnir214]

Subselects are possible in MySQL, but only if you're running MySQL 4.1. That version is alpha-revision code and should not be used for production systems.

Want the best answers? Ask the best questions:

http://www.catb.org/~esr/faqs/smart-questions.html

TANSTAAFL!!