SELECTing from a SELECT statement

dinger · #1 (**permalink**) 03-23-04, 11:12

Is there a way to do this in straight SQL: Execute a SELECT query, then execute a SELECT query on the results of the first query?

Thanks.

Pat Phelan · #2 (**permalink**) 03-23-04, 11:17

Assuming that your database engine supports derived tables, yes you can base one SELECT upon the results of another SELECT.

-PatP

alligatorsql.com · #3 (**permalink**) 03-23-04, 11:24

Hello,

what do you think about

SELECT * FROM
(SELECT * FROM query1 WHERE TAB=1)
WHERE FIELD = 10;

Hope that helps ?

Best regards
Manfred Peter
Alligator Company Software GmbH
http://www.alligatorsql.com

Pat Phelan · #4 (**permalink**) 03-23-04, 13:00

Don't you have to provide a table-alias for a derived table? I would expect you to need something like:

Code:

SELECT * FROM
   (SELECT * FROM query1 WHERE TAB=1) as A
   WHERE FIELD = 10;

for that to work.

-PatP

alligatorsql.com · #5 (**permalink**) 03-23-04, 14:09

Hello,

this works also without an alias ... but when you want to join
its better to use an alias like

SELECT *
FROM (SELECT * FROM table1) AS a,
table2 b
WHERE a.id = b.id

Best regards
Manfred Peter
Alligator Company Software GmbH
http://www.alligatorsql.com

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