You do not have to. The line:
y.colnames=x.colnames
does it for you, as long as the list of fields maps 1 to 1.
On Saturday, 21 July 2012 20:10:09 UTC-5, Cliff Kachinske wrote:
>
> This is great.
>
> I've not tried it yet, but I'm assuming I can alias the field names if the
> tables have different field names with the same data type.
>
> Is it possible to combine two field names into a single alias?
>
> Thanks
>
> On Friday, July 20, 2012 5:35:37 PM UTC-4, Massimo Di Pierro wrote:
>>
>> You can also to
>>
>> db=DAL()db.define_table('a',Field('name'))
>> db.define_table('b',Field('name'))
>> db.a.insert(name='Alex')
>> db.a.insert(name='Max')
>> db.a.insert(name='Tim')
>> db.b.insert(name='John')
>> db.b.insert(name='Jack')
>> def union(x,y):
>> y.colnames=x.colnames
>> return x|y
>>
>> *rows = union(db().select(db.a.name),db().select(db.b.name)).sort(lambda
>> row: row.name)*
>>
>> for row in rows: print row.name
>>
>>
>> This does not translate into a union and runs at the web2py level. Mind
>> that while testing I notice a discrepancy between docs and implementation
>> of the sort() method. I fixed it in trunk. This code will only work with
>> trunk.
>>
>> Massimo
>>
>>
>> On Friday, 20 July 2012 16:08:16 UTC-5, Cliff Kachinske wrote:
>>>
>>> You can avoid a union like so:
>>>
>>> rows = db(q).select(r).as_list()
>>> rows.extend(db(qq).select(rr).as_list()
>>>
>>>
>>>
>>> You have to access attributes dictionary fashion, not in dot notation.
>>> Could be a problem for SQLTABLE and descendants.
>>>
>>> Google 'sort list of dictionaries' to see how to sort it.
>>>
>>> On Friday, July 20, 2012 3:00:58 PM UTC-4, Andrew wrote:
>>>>
>>>> Does that mean sample, example, random have to have identical
>>>> structures ?
>>>> What if I just want the id and name columns ? How do I select just
>>>> those in a union scenario?
>>>>
>>>> I know massimo doesn't like unions, but they are required sometimes.
>>>> I am visualizing object relationships in a graph (picture something like
>>>> http://bost.ocks.org/mike/fisheye ) and I want to get one list of
>>>> nodes. I've only done it with executesql so far.
>>>>
>>>
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