MySQL 5.7 Release Notes
It is possible to specify statements over multiple lines. When
in Python or JavaScript mode, multiple-line mode is
automatically enabled when a block of statements starts like in
function definitions, if/then statements, for loops, and so on.
In SQL mode multiple line mode starts when the command
\ is issued.
Once multiple-line mode is started, the subsequently entered statements are cached.
For example:
mysql-sql> \
... create procedure get_actors()
... begin
... select first_name from sakila.actor;
... end
...
mysql-sql>