Re: Lua and Postgres

[Marc Balmer <marc@...>]

Well, it looks like we suddenly have an abundance of interfaces to
PostgreSQL ;)  Having a choice is always a good thing.

[...]


> https://github.com/STPeters/luapgsql

This lacks licensing information (or I did not find it).

> 
> local res = db:exec("SELECT name FROM persons WHERE id = $1", {id})
> for r in res:rows()
>     print(r.name)
> end

A good idea, maybe I "steal" it.

> 
> 
>> You get the idea...  Currently we are trying to make use of PostgreSQL's
>> asynchronous notification feature, linking a notificatin to the
>> execution of a Lua function:
>>
>> db:listen('AN_EVENT', function()
>>    print('Event AN_EVENT was signalled')
>> end)
>>
>> Then when e.g. on a psql prompt you enter 'notify AN_EVENT;', above
>> function would be called.
> 
> my fork of luapgsql:
> https://github.com/edo1/luapgsql

No license information, either.

> 
> db:exec('LISTEN somenotify')
> -- wait indefinitely for NOTIFY:
> db:notifywait()
> -- OR wait for NOTIFY, up to six seconds
> db:notifywait(6)
> 
> for my needs NOTIFY-wait function is better, but if someone need
> NOTIFY-driven callback - it can be added as well.

To be honest, I left out a small, but important detail:  Our
implementation works in an X11 context only, i.e. we use X11 library
calls internally.