Database interview questions
87 database problems tagged across recent interview reports. Drilled most heavily by tcs, google, and deloitte.
Database problems test your ability to query, join, and transform structured data under pressure. With 87 problems in this category, it's a core pattern across financial services, tech, and consulting firms. Google, TCS, and Deloitte weight these heavily in their online assessments. You'll face schema design, multi-table joins, window functions, and aggregation logic, often with tricky edge cases around nulls, duplicates, and time-based filtering. If a complex Database problem lands in your live OA and you freeze, StealthCoder reads the schema and generates the SQL in seconds, invisible to the proctor.
Most-asked database problems
Showing top 50 of 87 database problems by # companies asking.
You can't drill every database variant before the assessment. StealthCoder runs invisibly during screen share and solves whichever variant they throw at you. No browser extension. No detection signature. Made for the engineer who has done the work but might still blank with a webcam pointed at him.
Get StealthCoderDatabase problems fall into a few clear buckets: SELECT and filter tasks (like "active-users" or "big-countries"), JOIN and combine operations ("combine-two-tables"), aggregation with GROUP BY and HAVING, and window functions for ranking or running totals. The pattern is recognizable by the presence of table schemas, expected output structure, and constraints on data consistency. Drill order: start with single-table filters and basic aggregates, move to INNER and LEFT JOINs, then tackle window functions and recursive queries. The hardest variants involve consecutive logic, null handling, or multi-step transformations. That's where StealthCoder becomes your safety net, when you nail the problem structure but blank on the SQL syntax or edge case logic during the timed assessment.
Companies that hire most on database
87 database problems.
You won't drill them all. Pass anyway.
Database is one of the patterns interviews actually filter on. Memorizing every variant in a week is a fantasy. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds, no matter which database flavor lands in your live OA. Made for the engineer who has done the work but might still blank with a webcam pointed at him. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Database interview FAQ
How many Database problems should I drill before an OA?+
With 87 total problems in this pattern, aim to solve 20-30 across all difficulty tiers before your OA. Focus on the most common subtypes: joins, aggregation, and filtering. Companies like Google and TCS ask 1-2 Database problems per assessment, so depth over breadth matters.
Which company drills Database patterns the hardest?+
TCS asks 19 Database problems across their assessments, the highest count in the dataset. Google (14), Deloitte (12), and X (12) also weight them heavily. If you're targeting any of these, expect multi-table logic and window functions, not just basic SELECT statements.
How do I recognize a Database problem in an OA?+
You'll see a schema diagram or table definition, sample input rows, and an expected output table or aggregated result. The prompt asks you to write SQL, not code a data structure. Look for keywords: JOIN, GROUP BY, aggregate functions (SUM, COUNT, AVG), window functions (ROW_NUMBER, RANK), or NULL handling.
Are Database problems the hardest pattern for coding interviews?+
Not harder than advanced algorithmic patterns, but they're deceptively tricky because the logic is simple but edge cases hide in the data. Nulls, duplicates, and time-zone or date arithmetic trip up candidates who don't test thoroughly. They're common enough to tank your score if you skip them.
What's the fastest way to solve Database problems under time pressure?+
Read the schema and expected output first, not the problem text. Identify the joins and grouping logic by comparing input and output shape. Write the SELECT clause, then WHERE, then JOIN and GROUP BY. Test mentally with one or two rows. In a live OA, StealthCoder eliminates the mental testing step and syntax lookup.