o:sqlite-users-
boun...@sqlite.org] On Behalf Of Yuriy Kaminskiy
Sent: Wednesday, 05 September, 2012 19:53
To: sqlite-users@sqlite.org
Subject: Re: [sqlite] classic update join question
Igor Tandetnik wrote:
On 9/5/2012 12:38 PM, E. Timothy Uy wrote:
I have a column in table 'alpha' wh
Many thanks to all of you who took the time to correct my misunderstanding of
basic SQL.
I ran a little test in PostgreSQL (which is the quickest thing I have to play
with), and of course, you are all correct and the query does work as designed.
I was trying to figure out how to think about it
nt the
update expressed.
---
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> -Original Message-
> From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-
> boun...@sqlite.org] On Behalf Of Yuriy Kaminskiy
> Sent: Wednesday, 05 September, 2012 19:
On 9/5/2012 9:53 PM, Yuriy Kaminskiy wrote:
Igor Tandetnik wrote:
On 9/5/2012 12:38 PM, E. Timothy Uy wrote:
I have a column in table 'alpha' which I would like to populate with data
from table 'beta'. As far as I know, we cannot do an UPDATE using JOIN in
sqlite, but we can
UPDATE alpha SET f
On 6 Sep 2012, at 2:53am, Yuriy Kaminskiy wrote:
> Igor Tandetnik wrote:
>> On 9/5/2012 12:38 PM, E. Timothy Uy wrote:
>>> Will the database really be doing a select in beta for
>>> every single line in alpha?
>>
>> Yes - same as when implementing a join. How do you think a join is
>> performed
Igor Tandetnik wrote:
> On 9/5/2012 12:38 PM, E. Timothy Uy wrote:
>> I have a column in table 'alpha' which I would like to populate with data
>> from table 'beta'. As far as I know, we cannot do an UPDATE using JOIN in
>> sqlite, but we can
>>
>> UPDATE alpha SET frequency = (SELECT frequency FRO
September, 2012 18:18
> To: 'General Discussion of SQLite Database'
> Subject: RE: [sqlite] classic update join question
>
> > Update alpha
> >Set alpha.value = beta.value
> > From alpha, beta
> > Where alpha.key = beta.key
> >
> > (which is
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> > -Original Message-
> > From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-
> > boun...@sqlite.org] On Behalf Of E. Timothy Uy
> > Sent: Wednesday, 05 September, 2012 14:11
> &
---Original Message-
> From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-
> boun...@sqlite.org] On Behalf Of E. Timothy Uy
> Sent: Wednesday, 05 September, 2012 14:11
> To: General Discussion of SQLite Database
> Subject: Re: [sqlite] classic update join question
>
&
On Sep 5, 2012, at 11:00 PM, Igor Tandetnik wrote:
>> And such statement should raise an exception if the scalar sub-query returns
>> multiple rows, no?
>
> Definitely not in SQLite. I don't believe it would do that in other DBMS
> either, but won't bet on it. SQLite would take the value from
On 9/5/2012 4:54 PM, Petite Abeille wrote:
On Sep 5, 2012, at 10:38 PM, Igor Tandetnik wrote:
A select statement that would most closely resemble your update statement would
look like this:
select frequency, (select frequency from beta where beta.term = alpha.term)
from alpha;
This stateme
On Sep 5, 2012, at 10:38 PM, Igor Tandetnik wrote:
> A select statement that would most closely resemble your update statement
> would look like this:
>
> select frequency, (select frequency from beta where beta.term = alpha.term)
> from alpha;
>
> This statement will always return exactly as
On 9/5/2012 4:35 PM, Igor Tandetnik wrote:
On 9/5/2012 4:32 PM, E. Timothy Uy wrote:
Igor, what happens if there are multiple hits for
SELECT frequency FROM beta WHERE beta.term
= alpha.term
There can't be multiple hits, or even a single hit. This statement will
not run, as it's not syntactic
On 9/5/2012 4:32 PM, E. Timothy Uy wrote:
Igor, what happens if there are multiple hits for
SELECT frequency FROM beta WHERE beta.term
= alpha.term
There can't be multiple hits, or even a single hit. This statement will
not run, as it's not syntactically valid.
--
Igor Tandetnik
___
Igor, what happens if there are multiple hits for
SELECT frequency FROM beta WHERE beta.term
= alpha.term
(there aren't but, it is possible for there to be). Rob could be right in
a sense.
On Wed, Sep 5, 2012 at 1:28 PM, Igor Tandetnik wrote:
> On 9/5/2012 4:20 PM, Rob Richardson wrote:
>
>>
On 9/5/2012 4:20 PM, Rob Richardson wrote:
Well, I think you want a where clause on your main UPDATE query. What you
wrote will set the frequency of every record in the alpha table to the value
from the beta table, for every record in the beta table that matches an alpha
record. (It's late,
n...@sqlite.org]
On Behalf Of E. Timothy Uy
Sent: Wednesday, September 05, 2012 4:11 PM
To: General Discussion of SQLite Database
Subject: Re: [sqlite] classic update join question
Dear Igor,
Are you saying that
UPDATE alpha SET frequency = (SELECT frequency FROM beta WHERE beta.term =
alpha.te
On 9/5/2012 4:11 PM, E. Timothy Uy wrote:
Are you saying that
UPDATE alpha SET frequency = (SELECT frequency FROM beta WHERE beta.term
= alpha.term)
is just as efficient as it gets and equivalent to an update using join (in
other dbs)?
I don't know what other DBMS are doing. In SQLite, this u
Dear Igor,
Are you saying that
UPDATE alpha SET frequency = (SELECT frequency FROM beta WHERE beta.term
= alpha.term)
is just as efficient as it gets and equivalent to an update using join (in
other dbs)? That would helpful to know. I do kind of imagine some kind of
black magic... ;)
On Wed, S
On 9/5/2012 12:38 PM, E. Timothy Uy wrote:
I have a column in table 'alpha' which I would like to populate with data
from table 'beta'. As far as I know, we cannot do an UPDATE using JOIN in
sqlite, but we can
UPDATE alpha SET frequency = (SELECT frequency FROM beta WHERE beta.term =
alpha.term
Hi sqlite-users,
I have a column in table 'alpha' which I would like to populate with data
from table 'beta'. As far as I know, we cannot do an UPDATE using JOIN in
sqlite, but we can
UPDATE alpha SET frequency = (SELECT frequency FROM beta WHERE beta.term =
> alpha.term)
or we can create a tem
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