[sqlalchemy] Re: checking a relationship exists

2009-09-22 Thread joeformd
thanks - but how does that query specify a town? It seems like that would just return true if the current user had any town relationships? Or am I reading it wrong? On Sep 19, 5:46 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Sep 19, 2009, at 11:41 AM, joeformd wrote: When we

[sqlalchemy] Re: checking a relationship exists

2009-09-19 Thread joeformd
Thanks for the speedy response Michael, we came up with this: current_user_has_town = bool(session.query(User).filter (User.id==current_user.id).filter(User.towns.contains (current_user)).count()) which maybe has slightly clearer intent? --~--~-~--~~~---~--~~

[sqlalchemy] Re: checking a relationship exists

2009-09-19 Thread Michael Bayer
On Sep 19, 2009, at 10:19 AM, joeformd wrote: Thanks for the speedy response Michael, we came up with this: current_user_has_town = bool(session.query(User).filter (User.id==current_user.id).filter(User.towns.contains (current_user)).count()) which maybe has slightly clearer intent?

[sqlalchemy] Re: checking a relationship exists

2009-09-19 Thread joeformd
When we tried that it made a sql query to get all the towns (towns are loaded lazily) - that could be an awful lot of information, so this would be a much faster query On Sep 19, 4:33 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Sep 19, 2009, at 10:19 AM, joeformd wrote: Thanks for

[sqlalchemy] Re: checking a relationship exists

2009-09-19 Thread Michael Bayer
On Sep 19, 2009, at 11:41 AM, joeformd wrote: When we tried that it made a sql query to get all the towns (towns are loaded lazily) - that could be an awful lot of information, so this would be a much faster query so, the most succinct (and efficient) query of all is

[sqlalchemy] Re: checking a relationship exists

2009-09-18 Thread Michael Bayer
On Sep 18, 2009, at 7:44 PM, joeformd wrote: Is there a simple way in SQLA to check if a relationship exists between two rows in a many-to-many situation, where the relationship is defined using another table? eg. the join table might look like this: user_towns = Table('user_towns',