See where T-SQL differs from the ANSI standard in row limits, concatenation, NULL behavior, and practical query portability.
SQL SERVER – SSMS Does NOT Print NULL Values
Here is a very interesting question asked on the blog by Karthik. I really liked the question and I would like to discuss this here about SSMS doe snot Print NULL values.
Concat Strings in SQL Server: SQL in Sixty Seconds #035
To concat strings in SQL Server, use the + operator or the CONCAT function. The tests here show what each one does with NULL, numbers and dates, how the 8000 character limit cuts a result, and when CONCAT_WS or STRING_AGG is the better tool.
CHECK Constraints and NULL: Why Unknown Passes the Test
Why does a CHECK (Quantity > 0) happily store a row with no quantity? Three-valued logic, a small demo, and the NOT NULL fix.
DATEDIFF Counts Boundaries, Not Time: Getting Durations Right
A report can say one year of service after a single day. Here is why DATEDIFF does that, and what to use instead.
SQL SERVER – A Puzzle – Fun with NULL – Fix Error 8117
NULL is fun to ask about in interviews, since every answer I get is different. A short puzzle on NULL that raises Error 8117, and how to fix it.
SQL SERVER – Solution Part 2 – A Quick Puzzle on SQL JOIN and NULL – SQL Brain Teaser
Part 2 of the solution to my puzzle on SQL Join and NULL. Readers still email me answers every day, so here are more of the good ones they sent.