Can you help me with this query?
The query below will return all of the foreign keys in the current schema,
I get the ForeignKey name as FK_NAME and both the primary and foreign
table's name and schema, now I just need the columns involved in the
foreign key itself, there is a column called confkey in pg_constraint and
it's an array? It holds the column id
SELECT ct.oid, conname as FK_NAME, confkey, nl.nspname as PK_TABLE_SCHEMA,
cl.relname as PK_TABLE_NAME,
nr.nspname as FK_TABLE_SCHEMA, cr.relname as FK_TABLE_NAME, description
FROM pg_constraint ct
JOIN pg_class cl ON cl.oid=conrelid
JOIN pg_namespace nl ON nl.oid=cl.relnamespace
JOIN pg_class cr ON cr.oid=confrelid
JOIN pg_namespace nr ON nr.oid=cr.relnamespace
LEFT OUTER JOIN pg_description des ON des.objoid=ct.oid
WHERE contype='f'
mike.griffin@mygenerationsoftware.com wrote:
The query below will return all of the foreign keys in the current schema,
I get the ForeignKey name as FK_NAME and both the primary and foreign
table's name and schema, now I just need the columns involved in the
foreign key itself, there is a column called confkey in pg_constraint and
it's an array? It holds the column id
It is an array because foreign keys can have more than one participating
field -- how do you want that represented? Here's a way that you can get
an array of the participating field names, assuming you're using
Postgres 7.4.x:
create or replace function getattnames(oid, smallint[])
returns name[] as '
select array(select attname from pg_attribute
where attrelid = $1
and attnum = any ($2))
' language sql;
SELECT cl.relname as TABLE_NAME,
cr.relname as FK_TABLE_NAME,
getattnames(ct.conrelid, ct.conkey) as TBL_ATTS,
getattnames(ct.confrelid, ct.confkey) as FK_TBL_ATTS
FROM pg_constraint ct
JOIN pg_class cl ON cl.oid=conrelid
JOIN pg_namespace nl ON nl.oid=cl.relnamespace
JOIN pg_class cr ON cr.oid=confrelid
JOIN pg_namespace nr ON nr.oid=cr.relnamespace
LEFT OUTER JOIN pg_description des ON des.objoid=ct.oid
WHERE contype='f';
table_name | fk_table_name | tbl_atts | fk_tbl_atts
--------------------+--------------------+-------------+-------------
rule_and_refint_t3 | rule_and_refint_t1 | {id3a,id3b} | {id1a,id1b}
rule_and_refint_t3 | rule_and_refint_t2 | {id3a,id3c} | {id2a,id2c}
fktable | pktable | {fk} | {id}
clstr_tst | clstr_tst_s | {b} | {rf_a}
(4 rows)
HTH,
Joe
(please keep posts on the list so that others can follow along)
mike.griffin@mygenerationsoftware.com wrote:
Joe, I'm sorry but I cannot create functions or anything like that, it's
all has to be a select statement (or series of select statements). Users
pull up our product and browse all the databases and scheme's and such, if
we asked them to create functions or if we did it through calls it would
be intrusive.I tried to flatten out the function into a nested query but couldn't quite
get it right, is it possible to embed the select statement in the function
into the main select statement?
SELECT cl.relname as TABLE_NAME,
cr.relname as FK_TABLE_NAME,
array(select attname from pg_attribute
where attrelid = ct.conrelid
and attnum = any (ct.conkey)) as TBL_ATTS,
array(select attname from pg_attribute
where attrelid = ct.confrelid
and attnum = any (ct.confkey)) as FK_TBL_ATTS
FROM pg_constraint ct
JOIN pg_class cl ON cl.oid=conrelid
JOIN pg_namespace nl ON nl.oid=cl.relnamespace
JOIN pg_class cr ON cr.oid=confrelid
JOIN pg_namespace nr ON nr.oid=cr.relnamespace
LEFT OUTER JOIN pg_description des ON des.objoid=ct.oid
WHERE contype='f';
table_name | fk_table_name | tbl_atts | fk_tbl_atts
--------------------+--------------------+-------------+-------------
rule_and_refint_t3 | rule_and_refint_t1 | {id3a,id3b} | {id1a,id1b}
rule_and_refint_t3 | rule_and_refint_t2 | {id3a,id3c} | {id2a,id2c}
fktable | pktable | {fk} | {id}
clstr_tst | clstr_tst_s | {b} | {rf_a}
(4 rows)
HTH,
Joe
Import Notes
Reply to msg id not found: 39094.168.215.73.114.1087310492.squirrel@168.215.73.114
Joe, I'm sorry but I cannot create functions or anything like that, it's
all has to be a select statement (or series of select statements). Users
pull up our product and browse all the databases and scheme's and such, if
we asked them to create functions or if we did it through calls it would
be intrusive.
I tried to flatten out the function into a nested query but couldn't quite
get it right, is it possible to embed the select statement in the function
into the main select statement?
- Mike
Show quoted text
mike.griffin@mygenerationsoftware.com wrote:
The query below will return all of the foreign keys in the current
schema,
I get the ForeignKey name as FK_NAME and both the primary and foreign
table's name and schema, now I just need the columns involved in the
foreign key itself, there is a column called confkey in pg_constraint
and
it's an array? It holds the column idIt is an array because foreign keys can have more than one participating
field -- how do you want that represented? Here's a way that you can get
an array of the participating field names, assuming you're using
Postgres 7.4.x:create or replace function getattnames(oid, smallint[])
returns name[] as '
select array(select attname from pg_attribute
where attrelid = $1
and attnum = any ($2))
' language sql;SELECT cl.relname as TABLE_NAME,
cr.relname as FK_TABLE_NAME,
getattnames(ct.conrelid, ct.conkey) as TBL_ATTS,
getattnames(ct.confrelid, ct.confkey) as FK_TBL_ATTS
FROM pg_constraint ct
JOIN pg_class cl ON cl.oid=conrelid
JOIN pg_namespace nl ON nl.oid=cl.relnamespace
JOIN pg_class cr ON cr.oid=confrelid
JOIN pg_namespace nr ON nr.oid=cr.relnamespace
LEFT OUTER JOIN pg_description des ON des.objoid=ct.oid
WHERE contype='f';table_name | fk_table_name | tbl_atts | fk_tbl_atts
--------------------+--------------------+-------------+-------------
rule_and_refint_t3 | rule_and_refint_t1 | {id3a,id3b} | {id1a,id1b}
rule_and_refint_t3 | rule_and_refint_t2 | {id3a,id3c} | {id2a,id2c}
fktable | pktable | {fk} | {id}
clstr_tst | clstr_tst_s | {b} | {rf_a}
(4 rows)HTH,
Joe
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Hi Mike,<br>
<br>
If your foreign keys are all single-attribute, you can solve the
problem easily by only using the first element of each key.<br>
<br>
I like to use the following view to examine foreign keys:<br>
<br>
CREATE VIEW fkey AS<br>
SELECT t.relname AS tab, c.attname AS col, ft.relname AS ftab,
fc.attname AS fcol<br>
FROM pg_constraint fk<br>
INNER JOIN pg_class t ON fk.conrelid=t.oid<br>
INNER JOIN pg_attribute c ON fk.conkey[1]=c.attnum AND
c.attrelid=t.oid<br>
INNER JOIN pg_class ft ON fk.confrelid=ft.oid<br>
INNER JOIN pg_attribute fc ON fk.confkey[1]=fc.attnum AND
fc.attrelid=ft.oid<br>
WHERE fk.contype = 'f'<br>
;<br>
<br>
Note "confkey[1]=..." in the join condition. Of course, if the FK uses
multiple columns at either end the whole thing becomes rapidly
useless. <br>
<br>
HTH<br>
<br>
BJ<br>
<br>
<br>
<a class="moz-txt-link-abbreviated" href="mailto:mike.griffin@mygenerationsoftware.com">mike.griffin@mygenerationsoftware.com</a> wrote:
<blockquote
cite="mid46038.168.215.73.114.1087316384.squirrel@168.215.73.114"
type="cite">
<pre wrap="">Joe, I'm sorry but I cannot create functions or anything like that, it's
all has to be a select statement (or series of select statements). Users
pull up our product and browse all the databases and scheme's and such, if
we asked them to create functions or if we did it through calls it would
be intrusive.
I tried to flatten out the function into a nested query but couldn't quite
get it right, is it possible to embed the select statement in the function
into the main select statement?
- Mike
</pre>
<blockquote type="cite">
<pre wrap=""><a class="moz-txt-link-abbreviated" href="mailto:mike.griffin@mygenerationsoftware.com">mike.griffin@mygenerationsoftware.com</a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">The query below will return all of the foreign keys in the current
schema,
I get the ForeignKey name as FK_NAME and both the primary and foreign
table's name and schema, now I just need the columns involved in the
foreign key itself, there is a column called confkey in pg_constraint
and
it's an array? It holds the column id
</pre>
</blockquote>
<pre wrap="">It is an array because foreign keys can have more than one participating
field -- how do you want that represented? Here's a way that you can get
an array of the participating field names, assuming you're using
Postgres 7.4.x:
create or replace function getattnames(oid, smallint[])
returns name[] as '
select array(select attname from pg_attribute
where attrelid = $1
and attnum = any ($2))
' language sql;
SELECT cl.relname as TABLE_NAME,
cr.relname as FK_TABLE_NAME,
getattnames(ct.conrelid, ct.conkey) as TBL_ATTS,
getattnames(ct.confrelid, ct.confkey) as FK_TBL_ATTS
FROM pg_constraint ct
JOIN pg_class cl ON cl.oid=conrelid
JOIN pg_namespace nl ON nl.oid=cl.relnamespace
JOIN pg_class cr ON cr.oid=confrelid
JOIN pg_namespace nr ON nr.oid=cr.relnamespace
LEFT OUTER JOIN pg_description des ON des.objoid=ct.oid
WHERE contype='f';
table_name | fk_table_name | tbl_atts | fk_tbl_atts
--------------------+--------------------+-------------+-------------
rule_and_refint_t3 | rule_and_refint_t1 | {id3a,id3b} | {id1a,id1b}
rule_and_refint_t3 | rule_and_refint_t2 | {id3a,id3c} | {id2a,id2c}
fktable | pktable | {fk} | {id}
clstr_tst | clstr_tst_s | {b} | {rf_a}
(4 rows)
HTH,
Joe
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</pre>
</blockquote>
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</pre>
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<snip>
create or replace function getattnames(oid, smallint[])
returns name[] as '
select array(select attname from pg_attribute
where attrelid = $1
and attnum = any ($2))
' language sql;SELECT cl.relname as TABLE_NAME,
cr.relname as FK_TABLE_NAME,
getattnames(ct.conrelid, ct.conkey) as TBL_ATTS,
getattnames(ct.confrelid, ct.confkey) as FK_TBL_ATTS
FROM pg_constraint ct
JOIN pg_class cl ON cl.oid=conrelid
JOIN pg_namespace nl ON nl.oid=cl.relnamespace
JOIN pg_class cr ON cr.oid=confrelid
JOIN pg_namespace nr ON nr.oid=cr.relnamespace
LEFT OUTER JOIN pg_description des ON des.objoid=ct.oid
WHERE contype='f';
How about:
SELECT cl.relname as TABLE_NAME,
cr.relname as FK_TABLE_NAME,
(select array(select attname from pg_attribute
where attrelid = ct.conrelid
and attnum = any (ct.conkey))) AS TBL_ATTS,
(select array(select attname from pg_attribute
where attrelid = ct.confrelid
and attnum = any (ct.confkey))) AS FK_TBL_ATTS
FROM pg_constraint ct
JOIN pg_class cl ON cl.oid=conrelid
JOIN pg_namespace nl ON nl.oid=cl.relnamespace
JOIN pg_class cr ON cr.oid=confrelid
JOIN pg_namespace nr ON nr.oid=cr.relnamespace
LEFT OUTER JOIN pg_description des ON des.objoid=ct.oid
WHERE contype='f';
Note the function is no longer there ;-)
Nick
That doesn't complile, I don't think you can use a nested select where a
column goes? I get an error yelping about one of the select statements,
did you test it out? I'm using pgAdmin and don't think that it is the
problem?
Show quoted text
How about:
SELECT cl.relname as TABLE_NAME,
cr.relname as FK_TABLE_NAME,
(select array(select attname from pg_attribute
where attrelid = ct.conrelid
and attnum = any (ct.conkey))) AS TBL_ATTS,
(select array(select attname from pg_attribute
where attrelid = ct.confrelid
and attnum = any (ct.confkey))) AS FK_TBL_ATTS
FROM pg_constraint ct
JOIN pg_class cl ON cl.oid=conrelid
JOIN pg_namespace nl ON nl.oid=cl.relnamespace
JOIN pg_class cr ON cr.oid=confrelid
JOIN pg_namespace nr ON nr.oid=cr.relnamespace
LEFT OUTER JOIN pg_description des ON des.objoid=ct.oid
WHERE contype='f';Note the function is no longer there ;-)
Nick
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