With Postgres and Psycopg2, make sure your subquery returns more than zero records.
Postgres and Psycopg2 raise an exception when the belongs set is empty. On Monday, October 1, 2012 1:35:14 PM UTC-4, Richard wrote: > > Instead passing your tag, pass an inverse tag selection where you omit you > tag, then use not belongs : ~link.tag_id.belongs(subquery)... > > Where subquery will something like that : > > subquery=db(~db.TAGTABLE.TAGNAME.belongs((tag1,tag2,tagEtc))).select( > db.TAGTABLE.TAGNAME.id) > > Richard > > On Sat, Sep 29, 2012 at 1:51 PM, andrej burja > <andrej...@gmail.com<javascript:> > > wrote: > >> hi >> >> another question: >> there is number of tags: n = len(tags) >> and there is >> rows = db(data.id==link.record_id)\ >> (link.tag_id.belongs(subquery)).select( >> data.ALL, >> orderby=data.id, >> groupby=data.id, >> having=data.id.count()==n) >> >> so, if i have data1 with tags (news, sport) and data2 with tags (news, >> sport, football) >> and searching for tags: news, sport >> >> is the result data1 only or data1 and data2 >> if later, how to search for data with exactly entered tags (omit data >> with more tags) >> >> andrej >> >> >> On Monday, September 24, 2012 5:57:35 PM UTC+2, andrej burja wrote: >>> >>> hi >>> >>> it works >>> thank you >>> >>> andrej >>> >>> On Sunday, September 23, 2012 12:18:32 AM UTC+2, Massimo Di Pierro wrote: >>>> >>>> Looks like postgres is picky and wants in groupby all the selected >>>> fields in distinct. This should work: >>>> >>>> rows = db(data.id==tag.record_**id)\ >>>> (tag.name.belongs(tags)).sel**ect( >>>> data.ALL, >>>> orderby=data.id, >>>> groupby=data.id|data.value, >>>> distinct=True) >>>> >>>> On Saturday, 22 September 2012 15:00:07 UTC-5, andrej burja wrote: >>>>> >>>>> the code with problem: >>>>> >>>>> rows = db(data.id==tag.record_id)\ >>>>> (tag.name.belongs(tags)).selec**t( >>>>> data.ALL, >>>>> orderby=data.id, >>>>> groupby=data.id, >>>>> distinct=True) >>>>> >>>>> >>>>> >>>>> On Saturday, September 22, 2012 10:26:27 AM UTC+2, andrej burja wrote: >>>>>> >>>>>> hi >>>>>> >>>>>> i would like to use idea in book Application Development Cookbook - >>>>>> Efficienty search by tag. >>>>>> there are two functions: 'search_or' and 'search_and' >>>>>> everything is working fine on sqlite >>>>>> when i switch to postgres, there seems to be problem with 'groupby'. >>>>>> i got an error >>>>>> >>>>>> <class 'psycopg2.ProgrammingError'> column "data.value" must appear >>>>>> in the GROUP BY clause or be used in an aggregate function LINE 1: >>>>>> SELECT >>>>>> DISTINCT data.id, data.value FROM tag, data WHERE ((d... ^ >>>>>> when i remove 'groupby=....id" there is no error, but (of course) >>>>>> 'search_and' function doesn't work properly >>>>>> >>>>>> is this a bug related to postgres? >>>>>> >>>>>> andrej >>>>>> >>>>> -- >> >> >> >> > > --
