Raphael Bauduin writes:
> select count(t.trame_id) as count, v.voiture_num as voitureNum from
> arch_trames t left join voiture v on (v.tag_id=t.tag_id)
> where
> (t.recept_time >= 1243509320691)
> and exists (select v2.voiture_num from voiture v2 where v2.tag_id=v.tag_id)
> group by v.voiture_
Hi,
In some code I am taking over, I found this query:
select count(t.trame_id) as count, v.voiture_num as voitureNum from
arch_trames t left join voiture v on (v.tag_id=t.tag_id)
where
(t.recept_time >= 1243509320691)
and exists (select v2.voiture_num from voiture v2 where v2.tag_id=v.tag_id)
Thanks to those who responded, I see PL/PgSQL is the way to go
Regards, denis woodbury
on 10/11/08 1:32 PM, [NAME] at [ADDRESS] wrote:
> Denis Woodbury <[EMAIL PROTECTED]> writes:
>> I would like to know if this this type of statement can be used in
>> Postgresql
>
>> IF NOT EXISTS (SELECT 1
Denis Woodbury wrote:
Hi,
I would like to know if this this type of statement can be used in
Postgresql
IF NOT EXISTS (SELECT 1 FROM Table WHERE col1 = 'mystring' )
BEGIN
...
END
PostgreSQL doesn't have any sort of free block flow control; it doesn't
have an IF statement or similar in SQL. Y
Denis Woodbury <[EMAIL PROTECTED]> writes:
> I would like to know if this this type of statement can be used in
> Postgresql
> IF NOT EXISTS (SELECT 1 FROM Table WHERE col1 = 'mystring' )
> BEGIN
> ...
> END
I suspect you are trying to type that directly into SQL.
You need to be using plpgsql in
On Saturday 11. October 2008, Denis Woodbury wrote:
>Hi,
>
>I would like to know if this this type of statement can be used in
>Postgresql
>
>IF NOT EXISTS (SELECT 1 FROM Table WHERE col1 = 'mystring' )
>BEGIN
>...
>END
>
>If it can, any idea why I get this error.
>** Error **
>
>ER
Hi,
I would like to know if this this type of statement can be used in
Postgresql
IF NOT EXISTS (SELECT 1 FROM Table WHERE col1 = 'mystring' )
BEGIN
...
END
If it can, any idea why I get this error.
** Error **
ERROR: syntax error at or near "IF"
SQL state: 42601
Character: 2
> Hello!
>
> I vaguely remember that someone said somewhere that
> EXISTS runs faster than IN:
>
> SELECT * FROM table1 where field1 EXISTS (SELECT
> field4 FROM table2)
Move field1 into the subquery and join it to table2. See the FAQ for an
example.
--
Bruce Momjian
Hello!
I vaguely remember that someone said somewhere that
EXISTS runs faster than IN:
SELECT * FROM table1 where field1 EXISTS (SELECT
field4 FROM table2)
However, all I got from version 7.1.3 is:
ERROR: parser: parse error at or near "exists"
While below works:
SELECT * FROM table1 where
I'm running 7.1.3. What does 'rows=1' mean? The number of rows returned or the
number postgres has to look through?
Tom Lane wrote:
> Joseph Shraibman <[EMAIL PROTECTED]> writes:
>
>>Why does explain show more than one row, even if there is a LIMIT = 1?
>>
>
> What version are you runni
Joseph Shraibman <[EMAIL PROTECTED]> writes:
> Why does explain show more than one row, even if there is a LIMIT = 1?
What version are you running? I get results like
regression=# explain select * from tenk1 limit 1;
NOTICE: QUERY PLAN:
Limit (cost=0.00..0.03 rows=1 width=148)
-> Seq Scan
Why does explain show more than one row, even if there is a LIMIT = 1?
--
Joseph Shraibman
[EMAIL PROTECTED]
Increase signal to noise ratio. http://www.targabot.com
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Joseph Shraibman <[EMAIL PROTECTED]> writes:
> Then why does the explain say rows=1363 ?
That's the estimate of how many rows the inner SELECT would return, if
left free to return them all. You should get the same row count
estimate (though quite possibly a different plan) if you just do
an EXPL
Then why does the explain say rows=1363 ?
I don't mean to nitpick here, but maybe this is the symptom of a larger problem.
Tom Lane wrote:
> Joseph Shraibman <[EMAIL PROTECTED]> writes:
>
>>Well the total cost should be at least as big as the sub-costs, no?
>>
>
> Not if the sub-plan in questi
Joseph Shraibman <[EMAIL PROTECTED]> writes:
> Well the total cost should be at least as big as the sub-costs, no?
Not if the sub-plan in question is for an EXISTS. The sub-plan cost
is stated in terms of cost to retrieve all rows --- but the outer level
EXISTS isn't going to retrieve all rows,
> Stephan Szabo wrote:
> > On Tue, 21 Aug 2001, Joseph Shraibman wrote:
> >
> >
> >>Thank you, I was missing the parens.
> >>
> >>If I do an explain I see:
> >>
> >>-> Index Scan using m_u_and_p_key on m (cost=0.00..3035.22 rows=1363 width=12)
> >>
> >>
> >>even if I put a limit 1 on the sele
Stephan Szabo wrote:
> On Tue, 21 Aug 2001, Joseph Shraibman wrote:
>
>
>>Thank you, I was missing the parens.
>>
>>If I do an explain I see:
>>
>>-> Index Scan using m_u_and_p_key on m (cost=0.00..3035.22 rows=1363 width=12)
>>
>>
>>even if I put a limit 1 on the select. Why is that?
>>
>
Stephan Szabo wrote:
>>Limit (cost=48.39..48.39 rows=1 width=70)
>> -> Sort (cost=48.39..48.39 rows=2 width=70)
>> -> Hash Join (cost=18.46..48.38 rows=2 width=70)
>> -> Index Scan using u_p_key on u (cost=0.00..27.66 rows=48 width=28)
>> -> Hash (c
On Tue, 21 Aug 2001, Joseph Shraibman wrote:
> Thank you, I was missing the parens.
>
> If I do an explain I see:
>
> -> Index Scan using m_u_and_p_key on m (cost=0.00..3035.22 rows=1363 width=12)
>
>
> even if I put a limit 1 on the select. Why is that?
Is that the inner query (on the ex
Thank you, I was missing the parens.
If I do an explain I see:
-> Index Scan using m_u_and_p_key on m (cost=0.00..3035.22 rows=1363 width=12)
even if I put a limit 1 on the select. Why is that?
Stephan Szabo wrote:
> On Mon, 20 Aug 2001, Joseph Shraibman wrote:
>
>
>>I want to select a b
On Mon, 20 Aug 2001, Joseph Shraibman wrote:
> I want to select a boolean if there exists a row in another table that matches this
>one.
> So I did select ..., (select count(*) from table2 where ...) > 0 ...
> but that count(*) was taking forever. I know there is a better way to do it, but
>
I want to select a boolean if there exists a row in another table that matches this
one.
So I did select ..., (select count(*) from table2 where ...) > 0 ...
but that count(*) was taking forever. I know there is a better way to do it, but
whenever
I try to use EXISTS I get a syntax error. Wh
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