How to retrieve a comment/description from a table
Hello!
This psql command is very straight forward and promising:
COMMENT ON mytable IS 'This is my table.';
But how can I retrieve the particular comment from that table again?
Using \d+ gives you all the tables with their comments. I want a special
one.
And if that is not possible, can the \d+ results be obtained from a
system table or so?
Thanks,
Marcus
\d+ mytable will give you the comments for it
For system tables just do
\d+ pg_** substitute ** for system table name
HTH
On Fri, 23 Aug 2002, Marcus Claesson wrote:
Hello!
This psql command is very straight forward and promising:
COMMENT ON mytable IS 'This is my table.';But how can I retrieve the particular comment from that table again?
Using \d+ gives you all the tables with their comments. I want a special
one.And if that is not possible, can the \d+ results be obtained from a
system table or so?Thanks,
Marcus---------------------------(end of broadcast)---------------------------
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Darren Ferguson
\d+ mytable will give you the comments for it
This only gives me the same information as if I wrote '\d mytable', plus an
empty description column. I couldn't see my comment anywhere.
What I wish is to retrieve the comment with a sql question, which would work
if the '\d+ information' could be found in an actual table somewhere.
Regards,
Marcus
Marcus Claesson <marcus.claesson@angiogenetics.se> writes:
What I wish is to retrieve the comment with a sql question, which would work
if the '\d+ information' could be found in an actual table somewhere.
The descriptions are kept in pg_description. Although you can just do
"select from pg_description", the recommended retrieval method is the
obj_description() function. See
http://www.ca.postgresql.org/users-lounge/docs/7.2/postgres/functions-misc.html
http://www.ca.postgresql.org/users-lounge/docs/7.2/postgres/catalog-pg-description.html
regards, tom lane
Marcus Claesson wrote:
What I wish is to retrieve the comment with a sql question, which would
work
if the '\d+ information' could be found in an actual table somewhere.
select obj_description(oid, 'pg_class')
from pg_class
where relname = 'tablename';
--
Peter Gibbs
EmKel Systems
On Fri, 23 Aug 2002, Marcus Claesson wrote:
\d+ mytable will give you the comments for it
This only gives me the same information as if I wrote '\d mytable', plus an
empty description column. I couldn't see my comment anywhere.What I wish is to retrieve the comment with a sql question, which would work
if the '\d+ information' could be found in an actual table somewhere.
If you start psql with -E it will show you the queries it's running for
those backslash commands.
I believe \d+ table gives you column descriptions in that description
column.