empire-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From T-Rex <trex...@googlemail.com>
Subject Re: join same table twice in a query
Date Mon, 11 Jun 2012 18:29:57 GMT
Hello Joel,

as far as I know you have to create a second instance of your table if you
want to make a second join on the same column.
If i am correct you have to do  something like this:

cmd.join(db.TRIP.START_CITY_ID, CITY_instance1.ID <http://db.city.id/>);****

cmd.join(db.TRIP.END_CITY_ID, CITY_instance2.ID <http://db.city.id/>);


Can you try it and tell us if that works?


Pascal



2012/6/11 Becker, Joel <joel.becker@essvote.com>

> Hello. In a select query, how do I join the same table twice on two
> different fields?****
>
> ** **
>
> For example:****
>
> ** **
>
> cmd.select(…);****
>
> cmd.join(db.PERSON.TRIP_ID, db.TRIP);****
>
> cmd.join(db.TRIP.START_CITY_ID, db.CITY.ID);****
>
> cmd.join(db.TRIP.END_CITY_ID, db.CITY.ID);****
>
> ** **
>
> Then I want to get the start CITY.NAME and the end CITY.NAME.****
>
> ****
>
> -Joel****
>
> ** **
>

Mime
View raw message