On 6/22/2016 3:07 AM, Vlad Arkhipov wrote:
>
> CREATE TABLE t (id BIGINT NOT NULL PRIMARY KEY, name TEXT);
>
> The constraint that the data must satisfy is `there is no more than 3
> records with the same name`.
>
> I am not in control of queries that modify the table, so advisory
> locks can hardly be of help to me.
select name from t group by name having count(id)>3
will return all names with more than 3 records in a single query... now
the question is, what do you want to do with this information ?
--
john r pierce, recycling bits in santa cruz
