I second this BUT I still want to point out that .first() is a great tool
but it works at python level. In a "people" table holding 8M results,
you'll wait a lot. Use - WHENEVER and WHEREVER possible - orderby.
db(db.people.city == 'London').select(orderby=db.people.age,
limitby=(0,1)).first()
will land you the youngest of London. If several people are the same
"youth" there's an "having" method (but it requires a "groupby", which
seems to counteract the "complete record in the first query" requirement ).
The DBA in me would suggest a crafted executesql query involving WINDOWING
functions (that are the only ones giving the resultset in a single query)
but I guess you're not that into database internals.
I'd go for 2 queries or a subselect then
db(
(db.people.city == 'London') &
(db.people.age.belongs(
db(db.people.city == 'London')._select(db.people.age.min())
)).select()
).select(orderby=db.people.age, limitby=(0,1))
On Saturday, January 2, 2016 at 3:41:49 PM UTC+1, DenesL wrote:
>
> You could do
>
> db(db.people.city == "London").select(orderby=db.people.age).first()
>
>
>
>
>
> On Saturday, January 2, 2016 at 8:12:31 AM UTC-5, UG wrote:
>>
>> Hi,
>>
>> If i have the following table
>> ID
>> fist_name
>> last_name
>> city
>> age
>>
>>
>> I use the MIN to find the lowest age
>>
>> youngest = db(db.people.city ==
>> "London").select(db.people.age.min()).first()
>>
>> This will only give me the lowest age in the city. Is there a way to get
>> the complete record in the first query without having to resort to a second
>> query like
>>
>> result = db(db.people.age == youngest & db.people.city ==
>> "London").select()
>>
>> Thanks
>>
>
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