Top 50 MySQL Interview Questions and Answers

MongoDB is better suited for handling unstructured data and offers better scalability and performance compared to MySQL.

• MongoDB is a NoSQL database that allows for flexible and dynamic schema design.

• MongoDB is better suited for handling large amounts...read more

Query to find count of duplicate records in MySQL

• Use GROUP BY clause to group the records by the column(s) that may have duplicates

• Use HAVING clause to filter out the groups with count less than 2

• Use COUNT() function to count the number of records in...read more

DROP TABLE command is used to delete an entire table from the database, while DELETE command is used to delete specific rows from a table.

• DROP TABLE command deletes the entire table and its data, while DELETE command deletes specific rows from a tabl...read more

MySQL 8 version offers improved performance, security, and scalability.

• Improved performance with new features like common table expressions and window functions

• Enhanced security with default authentication plugin set to caching_sha2_password

• Increased...read more

Indexing in MySQL improves the speed of data retrieval by creating a sorted reference to the data.

• Indexes in MySQL are used to quickly locate rows in a table without having to search the entire table.

• They are created on columns in a table to speed up...read more

To set up master and slave for MySQL, configure replication settings on both servers.

• Configure server-id and log-bin settings in my.cnf file on both master and slave servers

• Create a replication user on the master server with REPLICATION SLAVE privile...read more

Postgres and MySQL are both popular relational database management systems, but they differ in various aspects.

• Postgres supports more advanced features like JSON and array data types, while MySQL has limited support for these.

• Postgres has better conc...read more

To create a table using MYSQL, use the CREATE TABLE statement followed by the table name and column definitions.

• Use the CREATE TABLE statement to create a new table

• Specify the table name after the CREATE TABLE statement

• Define the columns and their da...read more

TempDB in MySQL is a temporary database used for storing temporary data during query processing.

• TempDB is used for storing temporary tables, intermediate results, and other temporary data.

• It is automatically created by MySQL when needed and is droppe...read more

To copy a table in MySQL, use the CREATE TABLE statement with the SELECT statement.

• Use the CREATE TABLE statement with the SELECT statement to copy a table.

• Specify the new table name after the CREATE TABLE statement.

• Specify the original table name af...read more

The default join in MySQL is INNER JOIN.

• INNER JOIN is the most commonly used join in MySQL.

• It returns only the matching rows from both tables.

• Other types of joins include LEFT JOIN, RIGHT JOIN, and FULL OUTER JOIN.

MySQL is a specific relational database management system, while SQL is a language used to interact with databases.

• MySQL is a specific RDBMS, while SQL is a language used to interact with databases

• SQL is a standard language for querying and managing ...read more

JOIN is used in MySQL to combine data from two or more tables based on a related column between them.

• JOIN is used to retrieve data from multiple tables in a single query

• It is used to combine rows from two or more tables based on a related column betw...read more

I have experience in MySQL and database management including data modeling, query optimization, and performance tuning.

• Designed and implemented database schemas for various projects

• Optimized complex queries for improved performance

• Performed database ...read more

A view in MySQL server is a virtual table that is based on the result set of a SELECT query.

• Views do not store any data themselves, but display data from one or more tables based on the query used to create the view.

• Views can be used to simplify comp...read more

Stored procedures in MySQL are precompiled SQL statements that can be saved and reused.

• Stored procedures are used to improve performance and reduce network traffic.

• They can be used to encapsulate business logic and complex queries.

• They can also be us...read more

GROUP BY in MySQL is used to group rows that have the same values into summary rows.

• Used with SELECT statement to group rows based on one or more columns

• Can be used with aggregate functions like COUNT, SUM, AVG, etc.

• Helps in summarizing data and perf...read more

The phone number should be saved as a VARCHAR datatype in a mySQL database.

• Use VARCHAR datatype to store phone numbers in mySQL database

• Varchar allows for variable length and is suitable for storing phone numbers

• Specify a maximum length for the VARCH...read more

MySQL is a full-featured relational database management system, while SQLite is a lightweight, serverless, self-contained database engine.

• MySQL is designed for larger applications with client-server architecture, while SQLite is suitable for smaller ...read more

MySQL has two main engines: InnoDB and MyISAM.

• InnoDB is the default engine and supports transactions, foreign keys, and row-level locking.

• MyISAM is simpler and faster, but does not support transactions or foreign keys.

• Other engines include MEMORY, CS...read more

To migrate a MySQL database to the cloud, you can use tools like AWS Database Migration Service or manually export/import data.

• Use AWS Database Migration Service for seamless migration to AWS RDS

• Export MySQL database using mysqldump command and impor...read more

MySQL is open source and widely used, while MSSQL is proprietary and more expensive.

• MySQL is open source, while MSSQL is proprietary

• MySQL is free to use, while MSSQL requires a license

• MySQL is more widely used in web applications, while MSSQL is more...read more

Relationships between tables in MYSQL Db are established using foreign keys.

• Use the FOREIGN KEY constraint to link a column in one table to a column in another table.

• The column in the child table must have the same data type as the column in the pare...read more

To alter a table in MySQL, use the ALTER TABLE statement.

• Use the ALTER TABLE statement followed by the table name.

• Specify the modification you want to make, such as adding or dropping columns, changing data types, etc.

• Use the ADD, DROP, MODIFY, or CH...read more

To update in MySQL, use the UPDATE statement with the SET keyword to specify the columns to update and the WHERE clause to specify the condition.

• Use the UPDATE statement followed by the table name

• Use the SET keyword to specify the columns to update a...read more

In-memory DB stores data in RAM for faster access while MySQL stores data on disk.

• In-memory DB is faster than MySQL as it eliminates disk I/O operations.

• In-memory DB is suitable for real-time applications that require low latency.

• MySQL is suitable fo...read more

A procedure in MySQL is a set of SQL statements that perform a specific task and can be reused multiple times.

• Procedures are stored in the database and can be called from other SQL statements or programs.

• They can have input and output parameters, and...read more