On 8 Aug 2013, at 1:47 PM, Niphlod wrote:
> Although it doesn't raise an error, querying
> WHERE column = NULL
> doesn't return any result (unless you force a
> really-its-going-to-be-superdeprecated-dont-do-that-youre-going-to-hell mode
> in some backends)
OK, that was confusing me, until I re
> Thanks for this. I've been puzzling over it myself the last couple of
> days. It'd be helpful if your explanation, or at least a summary of it,
> appeared in The Book.
>
> Would .belongs() work as expected (over True/False/None)?
>
Yep. Think to belongs() (that translates to an IN clause) a
another piece of examples
>>> for row in db(db.thenulltest.thenullablefield.belongs([True])).select():
print row
...
>>> for row in db(db.thenulltest.thenullablefield.belongs([True,False])).
select(): print row
...
>>> for row in db(db.thenulltest.thenullablefield.belongs([True,False,None
]
Here :
https://groups.google.com/d/msg/web2py/hQGyg6fL1Ls/zhxcWg7BsjYJ
Was a type issue...
Richard
On Thu, Aug 8, 2013 at 3:47 PM, Richard Vézina
wrote:
> I have been quite puzzled with .belongs() in the pass... I don't remember
> exactly was the cause of my problem at that time, I think it w
I have been quite puzzled with .belongs() in the pass... I don't remember
exactly was the cause of my problem at that time, I think it was if I was
passing a list to .belongs() and it was empty. I think I had asking about
that and get a answer from Niphold to... Let me searche that...
Richard
On
On 8 Aug 2013, at 12:12 PM, Niphlod wrote:
> Until now I assumed the problem of @Richard is that if a row has column ==
> None, if he queries the table with column != True he expected the NULL row to
> show (because in python None is different from True).
>
> ~db.table.column=False will result
Until now I assumed the problem of @Richard is that if a row has column ==
None, if he queries the table with column != True he expected the NULL row
to show (because in python None is different from True).
~db.table.column=False will result in a WHERE NOT column = 'F'. You don't
get any row ho
Hmmm... That's not quite what I suggested.
I suggested WHERE NOT COLUMN = 'F' which I think would result in the OP
wants, True and NULL would be grouped together and False would be separate.
Or are you saying that web2py db adapters will take the construction
~db.table.column=False and turn
Thanks Niphold. I am aware of that, but forget about it sometimes :(
I need bool to be NULL as I have more room for system evolution... Some
bool field I set them to not null but some I keep them nullable that can
bring me more insight on what going on with the record...
Anyway thanks again... I
it would give the same result, its the exact same "mental-mistake"
if you negate the filter you get exactly what you would get negating the
operator
i.e. WHERE NOT column = 'T' matches exactly WHERE COLUMN <> 'T'
a column holding a NULL value is "non-existant" for any (and I mean, really
a
Not to be flip, but couldn't you just reverse the test and use
~(mytable.mybool==False)? That would be false for False and true for True
and None (NULL)
But I agree it is an interesting find, and I will watch out for this in my
own code. Thanks for posting!
-- Joe
On Wednesday, August 7, 20
If you never used a db backend dealing with NULL values is a little bit
different than dealing with None in python.
While it's true that in python False != None and True != None, it's not the
same in SQL.
As much as the db engine knows, a column with a NULL value has no data to
compare with, so
I expect it will include the NULL... I said different then TRUE I want the
rest... I didn't know I had to take care of this...
So I have to write this like that
db((db.mytable.id == 1) & (db.mytable.mybool != True) & (db.mytable.mybool
== None)).select()
Thanks
Richard
On Wed, Aug 7, 2013 at
what did you expect ?
Any query with a filter (unless IS NOT NULL) doesn't take into account the
NULL value.
It's a pretty standard behaviour in any SQL backend.
If you need to get all rows with both False AND None values, you should do
db((db.mytable.id == 1) & ((db.mytable.mybool != True) | (
Forgot to mention : web2py 2.4.7 postgres 9.1 under ubuntu 12.04 server 64
bit...
Richard
On Wed, Aug 7, 2013 at 5:00 PM, Richard wrote:
> Hello,
>
> Found this not working :
>
> db((db.mytable.id == 1) & (db.mytable.mybool != True).select()
>
> That translate as :
> SELECT * FROM mytable WHER
Hello,
Found this not working :
db((db.mytable.id == 1) & (db.mytable.mybool != True).select()
That translate as :
SELECT * FROM mytable WHERE mytable.id = 1 AND mytable.mybool <> 'T'
NO RECORD, BUT THERE IS A RECORD
If i change the select like this :
SELECT * FROM mytable WHERE mytable.id =
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