Interview Q&A / SQL & DBMS

INTERVIEW Q&A · 69 QUESTIONS

SQL & DBMS interview questions

Joins, keys, normalisation, indexes and transactions for placement and backend interviews.

  1. Write a query to calculate a running total of daily sales.

    Use SUM(amount) OVER (ORDER BY day) to get a cumulative sum. Add PARTITION BY to restart the total per group, and use ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW to be explicit.

    IntermediateQuick answerCoding1 min read