Style formating of multiline query, advise
steve at holdenweb.com
Wed Mar 18 18:06:15 CET 2009
Scott David Daniels wrote:
> someone wrote:
>> what is good :) style for multiline queries to database?...
>> query = """ SELECT * FROM (
>> SELECT a.columna, a.columnb, a.iso
>> FROM all a
>> WHERE (a.name = LOWER(%s)) ) AS c
>> JOIN other as b on c.gid = b.id
>> WHERE class = 'A'
>> ORDER BY population DESC
>> LIMIT %s;"""
> Also, for SQL, (A) why are you using nested joins?, and
> (B) always show what columns you want as output. SELECT * is a hack
> to make interactive use easier, not a durable way to write queries.
> query = """SELECT a.columna, a.columnb, a.iso, b.id, ...
> FROM all AS a, other as b
> WHERE a.name = LOWER(%s)
> AND a.gid = b.id
> AND b.class = 'A'
> ORDER BY population DESC
> LIMIT %s;"""
In more modern syntax this would be
SELECT a.columna, a.columnb, a.iso, b.id, ...
FROM all AS a
JOIN other AS b
ON a.gid = b.id
WHERE a.name = LOWER(%s)
AND b.class = 'A'
ORDER BY population DESC
or something similar. The fact that you don't write JOIN in your SQL
doesn't mean the database isn't performing a join to perform the query
... I agree the nested query was somewhat over the top.
Steve Holden +1 571 484 6266 +1 800 494 3119
Holden Web LLC http://www.holdenweb.com/
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