Re: Re: PostreSQL SQL for MySQL SQL

At 01:10 PM 2/6/2001 -0600, John Burski wrote:
>There is no "if exists" functionality in PostgreSQL.  However, you could
>probably create your own "if exists" type of functionality.  I've found
>that it's not really necessary.  I access my databases either
>interactively, via psql, via the Perl Pg module, or via PHP.  If you
>attempt to drop a database that doesn't exist, PostgreSQL will issue an
>error message.  If you're running interactively, you'll see the message;
>if you're accessing via a Perl module or PHP, you can check the query
>results to see if an error occurred.  I'm fairly certain that this same
>mechanism exists if you're using C or C++ to access your databases.

I'd prefer to skip the error message, because otherwise my regression test
suite will barf, saying something like "Test X failed due to SQL error". I
suppose I work in some code to catch this and swallow it.


>I'm not familiar with the "use Foo" functionality of MySQL, so I can't
>discuss it.

I think you may have answered it with your "\connect dbname" comment.
Provided that I can put that after the "create database" in the SQL script
and feed the whole mess to psql.


I'll give this stuff a try. Thanks to all who answered.

I think it's still a good idea to provided the "if exists" clause in a
future PostgreSQL version for these reasons:
         1. it's convenient
         2. it doesn't interfere with existing functionality or performance
         3. it makes porting from MySQL to PostgreSQL easier


-Chuck