sql snippets

Gave a link to the new php program schedule page from the schedule page 2 days back, so it is in some sort of public beta. Found some bugs, one of which was due to languageid being NULL in our local db. Solution was to make languageid 1 the default value for that field, so that future record inserts will automatically have it set (tested) and also ran

update file_information set languageid=1 where languageid is NULL

Struggled a bit to get the syntax right, with languageid ='', languageid = NULL , NOT (languageid>0 and languageid<9) and so on, till I googled the correct syntax for NULL.

One more snippet of SQL Gyaan is that to insert, update etc for fields with type interval / timestamp , the syntax is

UPDATE "file_information" SET "duration" = interval '00:01:09' where file_id = 2020

and so on. One has to do a sort of typecasting using the keyword interval. One can even say interval '1 hour' and so on. From http://www.linuxjournal.com/article/9618