WordPress connecting to SQL Azure

Microsoft makes WordPress on Azure easier, but a tricky situation arises when we need to use MsSQL instead of MySQL for WordPress on Azure. I recently did a project that we migrated a website where wordpress connected to MySQL DB to WordPress, then connected to MsSQL DB. I made many mistakes and encountered many issues so I would like to share them here in hopes you will spared some headaches.

Prerequisites

  1. WordPress
  2. WP-DB-AbstractionPlugin
    1. PHP extension sqlsrv driver installed (read this post