Most frequently asked My SQL interview questions – Every Developer should know

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.

Also, read PHP interview programs

My SQL interview questions

Let’s begin

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.

  1. Before Insert
  2. After Insert
  3. Before Update
  4. After Update
  5. Before Delete
  6. 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?

SELECT CURRENT_DATE(); 

 

Question6: How to display nth highest salary?

Answer:

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