As per my personal and professional experience by giving the interview for featured companies also at the time of doing client projects or web application. I feel that importance of My SQL is a must. Anytime or Anywhere probably you feel this. Also, I know that this is very tough to read 50-60 questions in bulk. So the better idea is to prepare all those in a small session rather than giving them to time in a whole day. So according to this, here we have the following 6 most frequently asked My SQL interview questions and I think every developer should know these.
My SQL Interview Questions
Question1: What is the difference between CHAR and VARCHAR?
Answer: VARCHAR is variable length whereas CHAR is fixed length.
TIP: If your content is a fixed size, you’ll get better performance with CHAR.
Question2: What is the difference between TRUNCATE and DELETE in MySQL?
Answer: The DELETE command deletes a row from a table where TRUNCATE deletes every row from a table permanently.
Question3: What are Triggers and how many Triggers are possible in My SQL?
Answer: Triggers are some set of code which executes in response to some events and there are only six triggers allow to use in My SQL database.
- Before Insert
- After Insert
- Before Update
- After Update
- Before Delete
- After Delete
Question4: What is the difference between FLOAT and DOUBLE?
Answer: FLOAT stores the decimal value up to 8 places and takes 4 bytes in memory.
DOUBLE stores the decimal value up to 18 places and takes 8 bytes in memory.
Question5: How to get the current date in My SQL?
Question6: How to display nth highest salary?
select distinct(salary) from employee order by salary desc limit n-1,1
So that’s all, I know these are not enough but if you have read this then might be it has taken only some couple of minutes. It’s better than to read all 50-60 questions at a time with half attention.
Anyways, Thanks for reading this full article and I’ll hope a better developer future for you.
BEST OF LUCK