On Sat, Dec 11, 2004 at 03:32:13PM +0100, Steinar H. Gunderson wrote: > On Sat, Dec 11, 2004 at 03:17:13PM +0100, Tomas Skäre wrote: > > select c.* from cjm_object c > > inner join > > (select max(timestamp) as timestamp,objectid,field from cjm_object > > group by objectid,field) t > > using(timestamp,objectid,field) > > where 1=1 and data is not null > > order by objectid,field; > > Usually, SELECT max(field) FROM table is better written in PostgreSQL as > SELECT field FROM table ORDER field DESC LIMIT 1. > > I don't see the point of "where 1=1", though...
I've seen that in generated queries. The generating program uses "WHERE 1=1" to simplify the addition of other conditions: instead of checking if it needs to add a WHERE and putting ANDs in the right places, it simply appends subsequent conditions with " AND condition". -- Michael Fuhr http://www.fuhr.org/~mfuhr/ ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
