Database Related

SQL Database Programmer Interview Questions

Being familiar with great SQL questions to ask candidates in the course of an interview with a developer can offer you some assistance with filtering out the best applicants from the ones who are not the most qualified. There is a tremendous contrast between “It worked flawlessly on my machine” and “It scales well at the time of production.” These inquiries will offer you some assistance with filtering out the rotten ones (no offenceJ) before you employ them.

  • What is the swiftest way to put in thousands of records into the database?
  • In SQL, what does the keyword “UNION” do? Also, what’s the variance between the UNION and UNION ALL?
  • Outline the different kinds of JOIN clauses that are supported by the ANSI-standard in SQL.
  • When the query below is type, what will be the result?

select case when null = null then ‘Yup’ else ‘Nope’ end as Result;

  • Can you identify the difference between Unique Key and Primary Key?
  • How can you tell if a query will scale for production?
  • When the query below is type, what will be the result?

SELECT * FROM runners WHERE id NOT IN (SELECT winner_id FROM races)

  • As a programmer, write a query in SQL using UNION ALL (not UNION) which makes use of the WHERE clause to remove duplicates. What situation will push you to do this?
  • What is a major difference between Delete and Truncate?
  • What do you understand by an execution plan? How can you view the execution plan and when are you required to use it?
  • What is the Object type used in storing an image in the database?
  • How many TRIGGERS can be created in MySQL?
  • What do you understand by indexes in Databases and mention their types
  • Heap tables. What are they?
  • What is the difference between a clustered index and a primary key?
  • What is your name on StackOverFlow?

With the current advancements of technology and the application of SQL to handle database queries, users of this language need to step up their game, so as to keep up with the trend.

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