Master MySQL Interview Questions: Essential Topics & Free Guide

BAT (Baidu, Alibaba, Tencent) often ask specific MySQL interview questions; this guide collects the most common ones to help candidates prepare.

Table of Contents

Database fundamentals

Data types

Storage engines

Indexes

Transactions

Locks

Views

Stored procedures and functions

Triggers

Common SQL statements

SQL optimization

Database optimization

Storage Engines

Common storage engines include:

InnoDB : Provides ACID transaction support, row‑level locking, and foreign‑key constraints, designed for large‑scale data.

MyISAM (original MySQL default): No transaction support, no row‑level locking or foreign keys.

MEMORY : Stores all data in memory for fast access, but offers low durability.

Indexes

An index is a special file (part of the InnoDB tablespace) that contains pointers to all records in a table. It is a sorted data structure, typically implemented with B‑tree or B+‑tree, that speeds up query and update operations.

Transactions

A transaction is an indivisible sequence of database operations that moves the database from one consistent state to another, ensuring atomicity, consistency, isolation, and durability (ACID).

Locks

When multiple transactions run concurrently, locks are used to control the order of access and prevent data inconsistency.

Triggers

A trigger is a user‑defined, event‑driven stored procedure attached to a table; it automatically executes a block of code when the specified event occurs.

The full set of interview questions and detailed explanations can be downloaded for free.