Practical SQL Query Interview Questions (SQL Server Queries examples with answers) In this part, we will see SQL practice questions which contain both complex SQL queries interview questions and basic SQL Inter
Comprehensive, community-driven list of essential SQL interview questions. Whether you're a candidate or interviewer, these interview questions will help prepare you for your next SQL interview ahead of time.
which minimizes duplication, denormalization intentionally adds redundancy. It’s done to speed up data retrieval by reducing the need for complex joins. While it can improve query performance, it may lead to data inconsistencies and increased storage needs. So, use denormalization judiciously to...
For more practice with JOIN clauses, check out our article on JOIN interview questions! 3. Why is this query not returning the expected results? We have 1000 total rows in the orders table: SELECT * FROM orders; -- 1000 rows in set (0.05 sec) And 23 of those orders are from the us...
SQL Interview Questions1. What is Pattern Matching in SQL? SQL pattern matching provides for pattern search in data if you have no clue as to what that word should be. This kind of SQL query uses wildcards to match a string pattern, rather than writing the exact word. The LIKE operator...
Interview Query — This platform is dedicated to helping data scientists practice their SQL. If you’re serious, it’s worth looking into, but it’s a paid service. TestDome — This is yet another good platform for interview practice. ...
The use of comparison operators like <,> or = can be done in a subquery. These kinds ofSQL Interview Questionsare a bit difficult to understand and answer accordingly. There are a lot ofSQL Interview Questionsapart from this, which the candidates must practice qualifying for the interview. ...
The goal of this article is to start with a fairly simple query and move towards more complex queries. We’ll examine queries you could need at the job interview, but also some you would need in real-life situations. So, buckle up, we’re taking off! Data Model As always, let’s ...
You can use it as an online tool for Oracle PLSQL exercises and interview preparation. You can use it as a personal Oracle PLSQL sandbox and playground. There is an unlimited amount of scenarios that you can use our Oracle PLSQL compiler to practise your SQL. Have Fun!Cookie...
Eventually, in an outer query, apply a WHERE filter and a COUNT() function on the result of the subquery. Solution of SQL Interview Question #3 Solution: SELECT department_name, AVG(salaries.salary) AS avg_salaries FROM employees JOIN salaries ON employees.employee_id = salaries.employee_id ...