DBMS & SQL · Full Mock 1
35 questions in two timed sections – executed SQL and DBMS theory – with negative marking, in the style of a technical round.
Technical tests
DBMS & SQL Online Test
Query-result and query-writing questions run on real tables, plus normalization, transactions and indexing.
- Topics
- 10
- Practice sets
- 30
- Full mocks
- 2
- Questions
- 450
SQL is asked in almost every software, data and backend interview, and DBMS theory is a core GATE CSE subject. These tests mix query-result questions, "which query is correct" questions and concept questions. Every SQL answer on this page was produced by running the query on the tables shown with it.
Full mocks
Test yourself like the real round
DBMS & SQL · Full Mock 2
35 fresh questions – no overlap with Mock 1 – covering NULL traps, window functions, puzzles, normal forms, isolation and indexing.
Topic-wise practice
Choose a topic and level
01DBMS and SQL Fundamentals
DBMS concepts, SQL command families, filtering and sorting, NULL and three-valued logic, CASE, functions and basic DML.
02Joins and Subqueries
INNER, LEFT, RIGHT, self and cross joins, NULL traps, NOT IN vs NOT EXISTS and correlated subqueries.
03Aggregates and GROUP BY
COUNT, SUM, AVG, MIN and MAX with NULLs, GROUP BY and HAVING, conditional aggregation and ROLLUP.
04Window Functions
ROW_NUMBER, RANK, DENSE_RANK, NTILE, LAG and LEAD, running totals, frames, top-N per group and gaps and islands.
05Keys and Constraints
Primary, candidate, super, foreign and composite keys, NOT NULL, UNIQUE, CHECK and DEFAULT, referential actions and key closures.
06ER Model and Relational Mapping
Entities, attributes, weak entities, cardinality and participation, specialisation, and turning an ER diagram into tables.
07Normalization
Functional dependencies, anomalies, 1NF to BCNF, 4NF, lossless and dependency-preserving decomposition, and minimal cover.
08Transactions and Concurrency
ACID, COMMIT and ROLLBACK, savepoints, isolation levels and read anomalies, serializability, locking, deadlocks and recovery.
09Indexing and Query Optimisation
B+ tree indexes, clustered and secondary indexes, composite and covering indexes, when indexes are ignored, EXPLAIN, and GATE index arithmetic.
10Advanced SQL Queries
Subqueries, CTEs and recursive CTEs, UNION/INTERSECT/EXCEPT, pivots, Nth-highest and duplicate puzzles, multi-table DML, views and triggers.
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