Niphlod, can you please explain why you're using method _select instead of
select in your code below? In there no need to connect to SQL to set
all_courses?
On Tuesday, September 24, 2013 3:35:34 PM UTC+2, Niphlod wrote:
>
> you can do that with
>
> all_courses = db(db.courses.id>0)._select(db.courses.memberid)
> all_members_not_in_courses = db(~db.members.id.belongs(all_courses))
>
> you can eventually throw in a distinct on db.courses.memberid if the
> number of courses rows is plenty.
>
> Il giorno martedì 24 settembre 2013 12:16:52 UTC+2, Michael Hall ha
> scritto:
>>
>> I am not the most awesome SQL person and as such I am having trouble
>> constructing a query I need.
>>
>> I have two tables in a database called "old". The parent table is called
>> "members" and there is a child table called "courses".
>>
>> #--------
>> old.define_table('members',
>> Field('id'),
>> Field('profile_id','string'),
>> Field('title','string'),
>> Field('firstname','string'),
>> Field('surname','string'),
>> Field('memberlevel','string'),
>> Field('lawfirm','string'),
>> Field('registerdate','date'),
>> Field('expirydate','date'),
>> Field('email','string'),
>> Field('telno','string'),
>> Field('address1','string'),
>> Field('address2','string'),
>> Field('address3','string'),
>> Field('town','string'),
>> Field('county','string'),
>> Field('postcode','string'),
>> Field('country','string'),
>> Field('notes','text'),
>> Field('memberstatus','string'),
>> migrate=False)
>>
>> old.define_table('courses',
>> Field('memberid',type='reference members',),
>> Field('profile_id','string'),
>> Field('course','string'),
>> Field('enroldate','string'),
>> migrate=False)
>>
>> I would like to select all records in the members table that are not
>> referenced by records in the courses table. I suppose it could be described
>> as the opposite of a join as I only want to select members that do not have
>> courses attached to them.
>>
>> Any help would be appreciated.
>>
>>
>>
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