After upgrading from CiviCRM 4.7.19 to 4.7.23, views related to CiviCRM are failing to load. The following error is visible on the view configuration page:
SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'FROM westernfriend_civicrm.civicrm_contact civicrm_contact LIMIT 1 OFFSET 0' at line 1
What should I do to resolve the above error, and restore our view functionality?
In this case, the answer was to carefully read through the upgrade instructions (step 15):
Clear Views' cache (for sites using Views 3 integration)
If you were using Views integration prior to this upgrade, you will need to go to Administration » Structure » Views » Settings » Advanced and press "Clear Views cache" for Views to capture changes in the CiviCRM Views integration code.