db(a) is a set db(a)(b) is a subset
db(a)(b)(c) is a subset of the subset etc. db(a)(b)(c).select(left=table.on(d)) is a join notice that table.on(d) is not a set, but a condition (that is why it is on the right hand side, not the left hand side). a,b,c,d etc can be expressions like (q1)&(q2) or (q1)|(q2) etc. Massimo On Jan 27, 5:05 pm, Baron <[email protected]> wrote: > thanks Massimo - that works. > Previously I had tried db.sales.on(db.sales.name==db.item.name) > (db.user.name=='bob') but it caused an error. > Do you know in what cases this form is allowed? > > Baron > > On Jan 27, 5:23 pm, mdipierro <[email protected]> wrote: > > > this should work > > > db().select(db.item.name,db.sales.price,left=db.sales.on > > ((db.sales.name==db.item.name)&(db.user.name=='bob')) > > > Massimo > > > On Jan 27, 12:06 am, Baron <[email protected]> wrote: > > > > hello, I'm having difficulty making restrictions to a left outer > > > join. > > > > I have these tables: > > > Item: name > > > Sale: name, user, price > > > > I want to select all the items with the prices of any sales for the > > > current user. > > > For example, given this data: > > > > Items: > > > apple > > > banana > > > orange > > > > Sales: > > > apple,bob,1 > > > apple,bill,0.5 > > > orange,bob,3 > > > > For bob I want to show: > > > apple,1 > > > banana, > > > orange,3 > > > > To do the left join I use: > > > db().select(db.item.name, db.sale.price, left=db.sale.on(db.item.name > > > == db.sale.name)) > > > Is there a way I can restrict this query to join for just a certain > > > user? > > > > thanks, Baron --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py Web Framework" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/web2py?hl=en -~----------~----~----~----~------~----~------~--~---
