Bug #76414 need a current_trx_id information function
Submitted: 20 Mar 2015 20:52
Reporter: Trey Raymond Email Updates:
Status: Open Impact on me:
None 
Category:MySQL Server Severity:S4 (Feature request)
Version: OS:Any
Assigned to: CPU Architecture:Any
Tags: functions, information

[20 Mar 2015 20:52] Trey Raymond
Description:
the CONNECTION_ID() function gives the current connection id, but there's no way to get a the current transaction id from within a set of queries.  would primarily be used by triggers, but it's a nice to have in many cases.  currently, querying innodb_trx is a sloppy workaround that involves a lot more work for the server, and also that table isn't 100% in sync, so there is the potential for data loss.

How to repeat:
start transaction;
-- execute any query here, info_schema doesn't have the trx id until something is run
select trx_id from information_schema.innodb_trx where trx_mysql_thread_id=connection_id();

Suggested fix:
add the function...