bad-db-fixer.sql

-- create table for bad db names
create table things(database_name text);

-- insert some junk into it
insert into things values ('db1'),('db2'),('db3');


-- create the dropper proc
--call database_deleter();
CREATE OR REPLACE PROCEDURE database_deleter()
AS $proc$
DECLARE
    database text;
BEGIN
    -- build the loop of db names from the table
    FOR database IN SELECT database_name
          FROM things
    LOOP 
   -- send a notice about what db is about to reach enlightenment 
   RAISE NOTICE 'DELETING: %', database;

   -- use dynamic SQL to plug the variable into the statement to be executed
   EXECUTE format('DROP DATABASE IF EXISTS %s', database )
    USING database;
   
    END LOOP;
END;
$proc$ LANGUAGE plpgsql;


-- call the procedure:
call database_deleter();


-- This does result in the following:
rob=# call database_deleter();                                                  
NOTICE:  DELETING: db1
ERROR:  DROP DATABASE cannot be executed from a function
CONTEXT:  SQL statement "DROP DATABASE IF EXISTS db1"
PL/pgSQL function database_deleter() line 9 at EXECUTE