What freshers are asked in SQL interviews, a 30-day study plan, a practice database you can create in a minute, and the habits that turn correct answers into offers.
Databases, tables, DBMS versus RDBMS, the five SQL command groups, constraints, primary versus unique keys, foreign keys, and DELETE versus TRUNCATE versus DROP.
Types of subqueries, EXISTS versus IN, the NOT IN with NULL trap, correlated subqueries, CTEs including recursive ones, and the set operators UNION, INTERSECT and EXCEPT.
ROW_NUMBER versus RANK versus DENSE_RANK with a worked tie example, Nth highest salary, top N per group, LAG and LEAD, and running totals with the right frame.
Clustered versus non-clustered indexes, seek versus scan, covering indexes, why wrapping a column in a function breaks an index (SARGability), and how to read an execution plan.
What normalization is and why it matters, the three anomalies it prevents, 1NF, 2NF, 3NF and BCNF with one running example, and when denormalizing is the right call.
ACID explained with a bank transfer, the BEGIN, COMMIT and ROLLBACK pattern in SQL Server, dirty reads, non-repeatable reads and phantoms, isolation levels, deadlocks, and identity gaps.
The 20 mistakes that cost freshers the most marks in SQL interviews, grouped by topic, with what to say or write instead.
The 50 most-asked SQL interview questions for freshers, grouped by topic and marked High, Medium or Low priority, each with a short answer you can say out loud.
What async and await really do, why you should not block on tasks, and the handful of rules that prevent most async bugs.
The everyday LINQ operators, why queries are lazy, and the mistakes that cause surprising results or repeated database calls.
How header, nav, main, article, section and friends give a page structure that search engines and screen readers can understand.