9

Is there a "elegant built-in" case-insensitive way to check if db is exists?

I've found only SELECT datname FROM pg_catalog.pg_database WHERE datname='dbname', but this is a CS check. The first thing that comes to mind to retrieve all db names and filter them by hand, but I think there is more elegant way to do it.

  • Why do you want a case insensitive check of a case sensitive item? – Evan Carroll Jun 27 '17 at 20:51
18

You can use:

SELECT datname FROM pg_catalog.pg_database WHERE lower(datname) = lower('dbname');

... however, database names are case sensitive, so attempting to connect to the DB name won't actually work unless you match the case correctly. This won't use any indexes on dbname, but it's rather unlikely that you'd have enough databases for this to matter.

Folks don't realize that because PostgreSQL case-folds unquoted identifiers to lower-case, so most of the time it looks case-insensitive for clients. In fact, "DatabaseName" and "databasename" are different things.

4

If you want a true/false answer you can use

select exists(
 SELECT datname FROM pg_catalog.pg_database WHERE lower(datname) = lower('dbname')
);

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