Can a primary key contain NULL values? No. Here is why primary key and NULL do not mix, and the simple interview question many candidates miss.
List All the Stored Procedure Modified in Last Few Days – Interview Question of the Week #070
In the interview and I end up seeing candidates failing to answer this question about the Stored Procedure Modified recently.
SQL SERVER – Q&A: SQL Clustering Virtual Server Name and Instance Name
Basic SQL Clustering questions from a team new to cluster installs, like whether a new clustered instance needs a new virtual server name, answered one by one.
How to Insert Multiple Rows in a Single SQL Query – Interview Question of the Week #069
Interview question: write one script that inserts multiple rows in a single SQL query and runs unchanged in SQL Server, MySQL and PostgreSQL. Here is my answer.
SELECT One by Two – Interview Question Extended – Part II
After my SELECT One by Two puzzle, I played with a small extension: three queries mixing 1. and 1/2. Can you guess what each one returns and why?
What is Difference Between HAVING and WHERE – Interview Question of the Week #068
Clients sometimes interview me, and my answers from experience do not always match the textbook. Last week’s Interview Question: HAVING versus WHERE.
SELECT One by Two – Why Does SELECT 1/2 Returns 0 – Interview Question of the Week #067
Why does SELECT 1/2 return 0 in SQL Server and not 0.5? Beginners often think it is a bug. Here is the SELECT One by Two answer, explained simply.