full join question...

Started by Henriksen, Jonas Fabout 20 years ago8 messagesgeneral
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#1Henriksen, Jonas F
jonas.f.henriksen@imr.no

Hi,

I'm working with postgres and I have a question regarding a self-join on
my table (se below for table definition and testdata):
I want to retrieve all depths that have either a measuretype=1040 or a
measuretype=4001 or both. I've tried:

select * from
testtable t1
full outer join testtable t2
on( t1.operation=t2.operation and t1.depth=t2.depth
and t1.measuretype=1040 and t2.measuretype=4001)
where t1.operation=824419

This however does not restrict t1.measuretype to only 1040 but retrieves
all values for t1.

Have also tried using t1.measuretype=1040 in the where-condition:

select * from
testtable t1
full outer join testtable t2
on( t1.operation=t2.operation and t1.depth=t2.depth
and t1.measuretype=1040 and t2.measuretype=4001)
where t1.operation=824419
and t1.measuretype=1040

depth | measuretype | operation | depth | measuretype | operation
-------+-------------+-----------+-------+-------------+-----------
100 | 1040 | 824419 | | |
74 | 1040 | 824419 | 74 | 4001 | 824419
49 | 1040 | 824419 | 49 | 4001 | 824419
29 | 1040 | 824419 | | |
19 | 1040 | 824419 | | |
9 | 1040 | 824419 | 9 | 4001 | 824419
4 | 1040 | 824419 | 4 | 4001 | 824419

...which gives the result I want (jippiiii?), but would return to few
rows if t1.measuretype=1040 only was found on some depths, like if you
switch t1 and t2:

select * from
testtable t1
full outer join testtable t2
on( t1.operation=t2.operation and t1.depth=t2.depth
and t1.measuretype=4001 and t2.measuretype=1040)
where t1.operation=824419
and t1.measuretype=4001

depth | measuretype | operation | depth | measuretype | operation
-------+-------------+-----------+-------+-------------+-----------
74 | 4001 | 824419 | 74 | 1040 | 824419
49 | 4001 | 824419 | 49 | 1040 | 824419
9 | 4001 | 824419 | 9 | 1040 | 824419
4 | 4001 | 824419 | 4 | 1040 | 824419

Anyone know how I can make this query so it returns all rows for all
measuretypes, regardless of which is joining which?

All help apreciated (hope you understand what I want to do...),

regards Jonas:)))

Testdata and testtable definition:

CREATE TABLE testtable (
depth integer,
measuretype integer,
operation integer
);

INSERT INTO testtable VALUES (100, 1100, 824419);
INSERT INTO testtable VALUES (100, 1080, 824419);
INSERT INTO testtable VALUES (100, 1060, 824419);
INSERT INTO testtable VALUES (100, 1040, 824419);
INSERT INTO testtable VALUES (74, 4002, 824419);
INSERT INTO testtable VALUES (74, 4001, 824419);
INSERT INTO testtable VALUES (74, 1100, 824419);
INSERT INTO testtable VALUES (74, 1080, 824419);
INSERT INTO testtable VALUES (74, 1060, 824419);
INSERT INTO testtable VALUES (74, 1040, 824419);
INSERT INTO testtable VALUES (49, 4002, 824419);
INSERT INTO testtable VALUES (49, 4001, 824419);
INSERT INTO testtable VALUES (49, 1100, 824419);
INSERT INTO testtable VALUES (49, 1080, 824419);
INSERT INTO testtable VALUES (49, 1060, 824419);
INSERT INTO testtable VALUES (49, 1040, 824419);
INSERT INTO testtable VALUES (29, 1100, 824419);
INSERT INTO testtable VALUES (29, 1080, 824419);
INSERT INTO testtable VALUES (29, 1060, 824419);
INSERT INTO testtable VALUES (29, 1040, 824419);
INSERT INTO testtable VALUES (19, 1100, 824419);
INSERT INTO testtable VALUES (19, 1080, 824419);
INSERT INTO testtable VALUES (19, 1060, 824419);
INSERT INTO testtable VALUES (19, 1040, 824419);
INSERT INTO testtable VALUES (9, 4002, 824419);
INSERT INTO testtable VALUES (9, 4001, 824419);
INSERT INTO testtable VALUES (9, 1100, 824419);
INSERT INTO testtable VALUES (9, 1080, 824419);
INSERT INTO testtable VALUES (9, 1060, 824419);
INSERT INTO testtable VALUES (9, 1040, 824419);
INSERT INTO testtable VALUES (4, 4002, 824419);
INSERT INTO testtable VALUES (4, 4001, 824419);
INSERT INTO testtable VALUES (4, 1100, 824419);
INSERT INTO testtable VALUES (4, 1080, 824419);
INSERT INTO testtable VALUES (4, 1060, 824419);
INSERT INTO testtable VALUES (4, 1040, 824419);

--
Jonas F Henriksen
Institute of Marine Research
Norsk Marint Datasenter
PO Box 1870 Nordnes
5817 Bergen
Norway

Phone: +47 55238441

#2Niklas Johansson
spot@tele2.se
In reply to: Henriksen, Jonas F (#1)
Re: full join question...

On 5 apr 2006, at 16.39, Jonas F. Henriksen wrote:

Hi,

I'm working with postgres and I have a question regarding a self-
join on
my table (se below for table definition and testdata):
I want to retrieve all depths that have either a measuretype=1040 or a
measuretype=4001 or both.

All help apreciated (hope you understand what I want to do...),

Not sure I understand why you need a join... You say you want to
retrieve all depths that have certain measuretypes. Wouldn't the
following query do?

SELECT DISTINCT depth FROM testtable WHERE measuretype IN (1040, 4001);

Is there anything else you need from the query as well?

Mvh,

Niklas Johansson
Tel: 0322-108 18
Mobil: 0708-55 86 90

#3Henriksen, Jonas F
jonas.f.henriksen@imr.no
In reply to: Niklas Johansson (#2)
Re: full join question...

Hi,

ehh, sorry, yes, I also want to retrieve other values from the table,
but I left them out for clarity (which made it maby less clear...).
Maybe it makes more sense if you define the table as
CREATE TABLE testtable (
depth integer,
measuretype integer,
operation integer,
value float
);
...where I'm actually interested in the value...

Jonas:))

Show quoted text

On Wed, 2006-04-05 at 17:26 +0200, Niklas Johansson wrote:

On 5 apr 2006, at 16.39, Jonas F. Henriksen wrote:

Hi,

I'm working with postgres and I have a question regarding a self-
join on
my table (se below for table definition and testdata):
I want to retrieve all depths that have either a measuretype=1040 or a
measuretype=4001 or both.

All help apreciated (hope you understand what I want to do...),

Not sure I understand why you need a join... You say you want to
retrieve all depths that have certain measuretypes. Wouldn't the
following query do?

SELECT DISTINCT depth FROM testtable WHERE measuretype IN (1040, 4001);

Is there anything else you need from the query as well?

Mvh,

Niklas Johansson
Tel: 0322-108 18
Mobil: 0708-55 86 90

#4Niklas Johansson
spot@tele2.se
In reply to: Henriksen, Jonas F (#3)
Re: full join question...

On 5 apr 2006, at 18.37, Jonas F. Henriksen wrote:

ehh, sorry, yes, I also want to retrieve other values from the table,
but I left them out for clarity (which made it maby less clear...).
Maybe it makes more sense if you define the table as
CREATE TABLE testtable (
depth integer,
measuretype integer,
operation integer,
value float
);
...where I'm actually interested in the value...

Well, is there something else I don't get or couldn't you just select
that as well (perhaps without the DISTINCT then)?

SELECT depth, value FROM testtable WHERE measuretype IN (1040, 4001);

Sincerely,

Niklas Johansson

#5Niklas Johansson
spot@tele2.se
In reply to: Henriksen, Jonas F (#3)
Re: full join question...

On 5 apr 2006, at 18.37, Jonas F. Henriksen wrote:

ehh, sorry, yes, I also want to retrieve other values from the table,
but I left them out for clarity (which made it maby less clear...).
Maybe it makes more sense if you define the table as
CREATE TABLE testtable (
depth integer,
measuretype integer,
operation integer,
value float
);
...where I'm actually interested in the value...

Well, is there something else I don't get or couldn't you just select
that as well (perhaps without the DISTINCT then)?

SELECT depth, value FROM testtable WHERE measuretype IN (1040, 4001);

Mvh,

Niklas Johansson
Tel: 0322-108 18
Mobil: 0708-55 86 90

#6Henriksen, Jonas F
jonas.f.henriksen@imr.no
In reply to: Niklas Johansson (#5)
Re: full join question...

Well, the problem is I want the result on one row for each depth, so it
will fit nicely into a table, like this:

depth measuretype1_value measuretype2_value
10 1.78 2.55
20 2.12
30 3.12
40 1.3 1.4

...with missing rows for a depth appearing as missing values...

Jonas:))

Show quoted text

On Wed, 2006-04-05 at 20:06 +0200, Niklas Johansson wrote:

On 5 apr 2006, at 18.37, Jonas F. Henriksen wrote:

ehh, sorry, yes, I also want to retrieve other values from the table,
but I left them out for clarity (which made it maby less clear...).
Maybe it makes more sense if you define the table as
CREATE TABLE testtable (
depth integer,
measuretype integer,
operation integer,
value float
);
...where I'm actually interested in the value...

Well, is there something else I don't get or couldn't you just select
that as well (perhaps without the DISTINCT then)?

SELECT depth, value FROM testtable WHERE measuretype IN (1040, 4001);

Mvh,

Niklas Johansson
Tel: 0322-108 18
Mobil: 0708-55 86 90

#7Tom Lane
tgl@sss.pgh.pa.us
In reply to: Henriksen, Jonas F (#6)
Re: full join question...

"Jonas F. Henriksen" <jonas.f.henriksen@imr.no> writes:

Well, the problem is I want the result on one row for each depth, so it
will fit nicely into a table, like this:

depth measuretype1_value measuretype2_value
10 1.78 2.55
20 2.12
30 3.12
40 1.3 1.4

I think what you have to do is filter the rows according to measuretype
*before* you join them. Something like

select * from
(select depth, value as measuretype1_value from testtable
where measuretype = 1040) ss1
full join
(select depth, value as measuretype2_value from testtable
where measuretype = 4001) ss2
using (depth);

regards, tom lane

#8Henriksen, Jonas F
jonas.f.henriksen@imr.no
In reply to: Tom Lane (#7)
Re: full join question...

Thanks Tom, that worked great!!

Regards Jonas:))

Show quoted text

On Wed, 2006-04-05 at 15:09 -0400, Tom Lane wrote:

"Jonas F. Henriksen" <jonas.f.henriksen@imr.no> writes:

Well, the problem is I want the result on one row for each depth, so it
will fit nicely into a table, like this:

depth measuretype1_value measuretype2_value
10 1.78 2.55
20 2.12
30 3.12
40 1.3 1.4

I think what you have to do is filter the rows according to measuretype
*before* you join them. Something like

select * from
(select depth, value as measuretype1_value from testtable
where measuretype = 1040) ss1
full join
(select depth, value as measuretype2_value from testtable
where measuretype = 4001) ss2
using (depth);

regards, tom lane