Only use DROP ... IF EXISTS for PostgreSQL 8.2 or later. [#400 state:…

…resolved]

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -553,7 +553,15 @@ def create_database(name, options = {})
       # Example:
       #   drop_database 'matt_development'
       def drop_database(name) #:nodoc:
-        execute "DROP DATABASE IF EXISTS #{quote_table_name(name)}"
+        if postgresql_version >= 80200
+          execute "DROP DATABASE IF EXISTS #{quote_table_name(name)}"
+        else
+          begin
+            execute "DROP DATABASE #{quote_table_name(name)}"
+          rescue ActiveRecord::StatementInvalid
+            @logger.warn "#{name} database doesn't exist." if @logger
+          end
+        end
       end