Category Archives: postgresql

mysql tip: finding duplicated records

Found here: http://mysql-tips.blogspot.com/2005/04/mysql-find-duplicate-repords-example.html
select address, count(address) as cnt
from mailing_list
group by address
having cnt > 1
order by cnt;

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sqlite doesn’t support more than one primary key in one table

This cost me several hours today.
Postgresql support multiple primary keys in one table, and I took granted that sqlite does the same thing when I did some prototype today.
And they have a good reason explained in the SQLite CVSTrac.
The odd thing is, if I specify two primary keys in sqlite, it won’t complain when creating […]

don’t create table with name ends "_seq"

postgresql use this kind of table to keep track of sequence.

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