Last week, I asked a very simple puzzle about SQL SERVER – Puzzle – Why Does UNION ALL Work but UNION Produces Error?. The puzzle was very simple and interesting both together. I got quite a few valid answers to the puzzle so far. You may check original puzzle post to see all the valid answers. In this blog post we will quickly discuss the answer of our puzzle.
You already know what UNION and UNION ALL operators do. They combine datasets while UNION keeps the distinct data, UNION ALL will retain all the data. You can read more about that over here: SQL SERVER – Difference Between Union vs. Union All – Optimal Performance Comparison. Let us see why does anyone all work, but union produces error in this puzzle.
Today, we will see a very interesting puzzle about data types and default values.
You need to answer-
1 The original datatype A and default value B
2 The new datatype C and new default value D
This puzzle, I have discovered accidentally. In one of the recent project, I had to display two dates next to each other. Now, when I was doing this, I accidentally did a mistake while I was typing that out. Indeed, this puzzle about strange results when adding two dates.
In the last puzzle, user had to write the shortest code to produce 0. I have received around 700 valid answers and while reading through the answers, I had a blast. I personally learned quite a lot from just administrating the quiz. Since that puzzle, I have received quite a few emails requesting to come up with next puzzle.
If you have not understood what I am going to talk in this blog post by just reading the title, I think you are a normal human like me. Just the other day I received an email from a blog reader with subject line as “Select Unique Data From a Column Exist in Two Different Table”.
Puzzle: Write a Shortest Code to Produce Zero.