Обсуждение: Two very basic questions..
Hello all, I don't see either of these in the faq or docs... Very basic: - how do I see details of the various constraints (e.g foreign keys) in psql client? Am I looking at a system-table query? - Er, what can I use as a comment character in a sql file? Multiple hashmarks seem to cause parse errors Cheers and apologies if I've missed these in the docs, colm
On 05.12.01 13:00 +0000(+0000), Colm McCartan wrote: > Hello all, > > I don't see either of these in the faq or docs... Very basic: > > - how do I see details of the various constraints (e.g foreign keys) in > psql client? Am I looking at a system-table query? Yes, all the data is in system tables. The developers manual has info on the contents of the system tables: http://www.postgresql.org/idocs/index.php?catalogs.html You can also try using psql -E to see what queries the \*-commands (eg. \dv) generate. > - Er, what can I use as a comment character in a sql file? Multiple > hashmarks seem to cause parse errors You can have two kinds of comments: -- single line comments /* and multiline comments */ - Einar Karttunen
On Wed, Dec 05, 2001 at 01:00:38PM +0000, Colm McCartan wrote: > - Er, what can I use as a comment character in a sql file? Multiple > hashmarks seem to cause parse errors Standard SQL comments, two hyphens. Like "--". I'm sure this is mentioned somewhere... HTH, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > Terrorists can only take my life. Only my government can take my freedom.
Thanks for the responses. Heres a summary: >>- how do I see details of the various constraints (e.g foreign keys) in >>psql client? Am I looking at a system-table query? >> > Yes, all the data is in system tables. > The developers manual has info on the contents of the system tables: > http://www.postgresql.org/idocs/index.php?catalogs.html > You can also try using psql -E to see what queries the > \*-commands (eg. \dv) generate. Probably the most useful source on this is the link I found on the Non-FAQ technical docs for postgres: http://techdocs.postgresql.org/redir.php?link=/techdocs/hackingreferentialintegrity.php This points out that foreign keys are just specialised constraints and gives a few useful queries and views for inspecting and altering them. >>- Er, what can I use as a comment character in a sql file? Multiple >>hashmarks seem to cause parse errors >> > > You can have two kinds of comments: > -- single line comments > /* and > multiline comments */ > > - Einar Karttunen Thanks again. colm
> - how do I see details of the various constraints (e.g foreign keys) in > psql client? Am I looking at a system-table query? Most of this can be seen with \d tableName (also see \? for more psql backslash commands) though I don't think foreign keys are shown. I am not exactly sure how to get that information, but you might try searching the mailing list archives. > - Er, what can I use as a comment character in a sql file? Multiple > hashmarks seem to cause parse errors -- this is a comment (I believe this is an SQL standard)