Re: pl sql to check if table of table_name exists - Mailing list pgsql-general

I'm glad to hear you got it working.

In explanation to my response:

the pg_class internal table lists all the relationships in the database.

relkind='r' means that the relation you are looking for is a table (relation), I believe that will also find views.

relname is the name of the object if your table is called parts

select * from pg_class where relkind='r' and relname='parts' will give you the pg_class record for the table if it exists and nothing if it doesn't.

you could also do a select count(*) or select 1 In any case if there is a resultset the table exists and if there is no resultset the the table does not.

Using the pg_tables view is a better idea in any case, as it is cleaner.

 

Sim

"Shaun Clements" <ShaunC@relyant.co.za> wrote in message news:100F78F2B203444BB161BBA7077FF6131CD89E@srldbexc003.relyant.co.za...

Hi Sim

 

Thanks for your response. I had it working from a previous post by Adam Tomjack.

<snip>

-- A list of tables:

SELECT schemaname, tablename FROM pg_tables;

-- Returns true if a table exists:

SELECT count(*)>0 FROM pg_tables

WHERE schemaname='...' AND tablename='...'

</snip>

 

 

Your response does not work for me. Perhaps you can explain the posted command

 

<snip>

* from pg_class where relkind='r' and relname=your_tablename

</snip>

 

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Shaun Clements

 

 

 -----Original Message-----
From: Sim Zacks [mailto:sim@compulab.co.il]
Sent: 10 March 2005 01:24 PM
To: pgsql-general@postgresql.org
Subject: Re: [GENERAL] pl sql to check if table of table_name exists

i mean

select * from pg_class where relkind='r' and relname=your_tablename

"Sim Zacks" <sim@compulab.co.il> wrote in message news:d0pamh$2l83$1@news.hub.org...

select your_tablename from pg_class where relkind='r'

"Shaun Clements" <ShaunC@relyant.co.za> wrote in message news:100F78F2B203444BB161BBA7077FF6131CD89C@srldbexc003.relyant.co.za...

Hi

Hate to ask, but it isnt obvious to me from the documentation.
How do I perform a query in pgplsql, to check it a table exists of a particular name.

Thanks in advance

Kind Regards,
Shaun Clements