How To Select Rows in MySQL with No Matching Entry in Another Table

Author: , May 16th, 2018

SELECT t1.id FROM tableOne t1 LEFT JOIN tableTwo t2 ON t1.id = t2.id WHERE t2.id IS NULL The “WHERE t2.id IS NULL clause” restricts the results to only those rows where the id returned from tableTwo is null. tableTwo.id will be NULL for all records from tableOne where the id is not found in tableTwo.

How To Select the Max Numeric in a Varchar Column in MySQL

Author: , October 2nd, 2015

I needed to automate the addition of new users with a sequential member’s ID in WordPress. Additionally, there were non-numeric entries in that column that had to be ignored. The wp_users.user_login column is a varchar(60) and so does not naturally handle numeric operations well at all. The solution is a combination of REGEXP and cast(): […]

Where To Find MySQL Sample my.cnf Configuration Files On Amazon Linux

Author: , February 9th, 2012

YMMV… /usr/share/doc/mysql-server-5.1.52