Rename a MySQL database

Recently I needed to rename a MySQL database I was working with to make way for another with the same name. When I looked around for how to do this it seemed that the only option was to create the new database and then copy each table to it, via INSERT...SELECTs or a dump and import. It was quite a large database and this would have been very time consuming.

After discussing it with a colleague we came up with another way to do it by using bash to iterate over each table in the schema and then use the RENAME TABLE command:

for TABLE in `mysql -u[USERNAME] -p[PASSWORD] [OLD DB] -e "SHOW TABLES" -B -N -s`; do mysql -u[USERNAME] -p[PASSWORD] [OLD DB] -e "RENAME TABLE [OLD DB].$TABLE TO [NEW DB].$TABLE"; done;

This worked a treat (I've been using my new database reliably for a while now) and was fast too!

Exclude certain files from a cp command

I needed to be able to exclude files with a certain extension from a cp command that was going to be executed automatically as part of a much larger script.

There doesn't seem to be any direct way to do this (e.g. cp --exclude...) and although there are several suggestions on the net on how to overcome this I found the neatest way was to use the tar command instead:

cd /copy/from/path
tar -czf /path/to/archive.tar.gz ./ --exclude=*.txt
cd /copy/to/path
tar -xzvf /path/to/archive.tar.gz

Of course this isn't ideal, creating a tar archive when it isn't necessary but the files I needed to copy weren't large and so it was nice and quick and dirty.