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Query Interview Questions · IT Interview Practice
Home
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#Query
#Query
28 questions
Explain INNER, LEFT, RIGHT and FULL JOIN.
SQL
#join
Junior
›
How does the SELECT statement work?
SQL
#query
Junior
›
How do you filter rows with WHERE?
SQL
#query
Junior
›
What are aggregate functions (COUNT, SUM, AVG, etc.)?
SQL
#query
Junior
›
How do GROUP BY and HAVING work?
SQL
#query
Junior
›
How do ORDER BY and LIMIT work, and how do you paginate?
SQL
#query
Junior
›
How do INSERT, UPDATE and DELETE work?
SQL
#query
Junior
›
How do you handle duplicates with DISTINCT?
SQL
#query
Junior
›
What are subqueries and how do you use them?
SQL
#query
Middle
›
What are UNION, INTERSECT and EXCEPT?
SQL
#query
Middle
›
How does the CASE expression work?
SQL
#query
Middle
›
What are common string and date functions?
SQL
#query
Middle
›
What is a self-join?
SQL
#query
Middle
›
What are window functions?
SQL
#query
Senior
›
What are Common Table Expressions (CTEs)?
SQL
#query
Senior
›
What is UPSERT (INSERT ON CONFLICT)?
PostgreSQL
#query
Junior
›
What does the RETURNING clause do?
PostgreSQL
#query
Junior
›
How do CTEs and recursive queries work in PostgreSQL?
PostgreSQL
#query
Middle
›
How do CRUD operations work in MongoDB?
MongoDB
#query
Junior
›
What query operators does MongoDB provide?
MongoDB
#query
Junior
›
How do find queries and projections work?
MongoDB
#query
Junior
›
How do you insert, update and delete documents?
MongoDB
#query
Junior
›
How do sorting and pagination work in MongoDB?
MongoDB
#query
Junior
›
How do you combine conditions with logical operators?
MongoDB
#query
Junior
›
What is the aggregation pipeline?
MongoDB
#query
Middle
›
What update operators does MongoDB provide?
MongoDB
#query
Middle
›
What advanced aggregation features does MongoDB offer?
MongoDB
#query
Senior
›
How do geospatial queries work in MongoDB?
MongoDB
#query
Middle
›