You can change the mysql prompt client so you know where you are.
Very usefull when you manage a lot of mysql databases and you forget which one :-)
For example, if I’m working on the FooBar projet, I can use this prompt :
mysql --prompt="@FooBar> "
Then I’ll have something like that :
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. @FooBar> show databases;
Neat ! Never lost in databases anymore :-D