Embedding comments in MySQL statements

Question

Does anyone know of a way to embed comments in MySQL statements? When I search for mysql and comments I get only ways to put comments in tables, etc

The idea, if I implement this the way my boss wants it, is to prepend the user id to the statement apparently so that when MySQL is analyzed later (via the binary log) we know who did what.

Example:
SELECT id
FROM customer
WHERE handle='JBH'

Would now show up as:
-- user:jwilkie
SELECT id
FROM customer
WHERE handle='JBH'

(or similar)

EDIT FOR CLARITY: The reason for this is that we have perl modules that are interfacing with MySQL and we are retrieving the user id by reading $ENV{USER} (which in this case is "jwilkie"). It is a situation where we have one MySQL user defined but multiple people running the perl mod.

Does anyone have experience with this? Many many thanks! Jane

Answer 1

Normally, comments are stripped before the SQL statement is recorded in the binary log. However, a nasty workaround is to pretend that ypur comment contains syntax for some future version of MySQL - eg. 9.99.99:

/*!99999 user:jwilkie */ insert into tbl values (yyy);

These comments will then be passed through into the binary log.

Answer 2

If you have control over the SQL queries being generated, then you should be able to embed comments in them programatically in your query builder.

Select queries don't go in the binary log, but the comments may make it into the slow query log, general query log, etc.

Here's a blog post from Percona that touches on the subject a bit, specifically in the context of mk-query-digest. It might help:

http://www.mysqlperformanceblog.com/2010/07/05/mk-query-digest-query-comments-and-the-query-cache/