T-SQL

May 07, 2020

What is the difference between putting a filter in the ON clause versus the WHERE clause?

In short, the filter placement could change the query results if the query uses an outer join. Left (right) outer joins add back non-matching rows from the left (right) table after the ON filter. A row might match the ON…

SQL Server T-SQL

December 20, 2016

Auditing Failed Logins

SQL server will by default write failed login attempts to the database error log. It's not only important to review failed login attempts for security reasons but also they are sometimes a symptom of another problem. One of the problems…

SQL Server Security Failed Logins T-SQL Error Log