MySQL Interview Questions

MySQL is the most widely used open-source relational database management system, frequently combined with PHP. It is quick, dependable, and simple to use on the web and server. Tables are used to store data in a MySQL database. A table is a group of connected data divided into rows and columns.

Some things to know about MySQL:

• MySQL compiles on many platforms and uses standard SQL. It is a SQL database management system with multiple threads and users.
• Users can work directly with a MySQL database using SQL by connecting to it through one of MySQL's standalone clients. MySQL, on the other hand, is typically used with other programs to create applications that can interact with relational databases.

These MySQL Interview Questions and Answers can be classified majorly into the following two categories:

• Fresher 
• Experienced 

Top 10 Frequently Asked MySQL Interview Questions

• What is MySQL
• What are the features of MySQL?
• What are the most common MySQL functions?
• How do you create a database in MySQL?
• What is the default size of the MySQL database?
• What are MySQL's technical requirements?
• What types of tables does MySQL support?
• How does MySQL add columns?
• What is MySQL's BLOB?
• How do I set up a MySQL Trigger?

MySQL Interview Questions For Freshers

1) What is SQL Server?

Microsoft created SQL Server, one of the database management systems (DBMS). DBMS are computer software programs that communicate with databases, users, and other programs. Data collection and analysis, as well as the definition, querying, creation, updating, and administration of the database, are the goals of SQL Server.

 

 

2) What is MySQL

MySQL is a popular web server database management system. It's highly scalable, so it can expand as the site does. These days, MySQL is the backbone of almost every website.

If you want to enrich your career and become a professional in SQL, then visit Mindmajix - a global online training platform: "SQL Server Training" This course will help you to achieve excellence in this domain.

3) Which programming language was used to develop MySQL?

MySQL features an integrated SQL parser, and the database is written in C and C++.

4) What are the features of MySQL?

MySQL offers support for multiple operating systems, a diverse selection of interfaces for application programming, and a large number of stored procedures, such as triggers and cursors, that are useful in the administration of databases.

 

 

5) What is MySQL Server's default port number?

The port number 3304 is used by default by MySQL Server. 

In TCP/IP, port number 1433 is another standard default port for SQL Server.

Related Article: MongoDB Vs MySQL

6) What are the most common MySQL functions?

Following are some of the most frequently used MySQL commands:

• CURRDATEO: The function that returns the current time or date.
• NOWO: The function returns the current date and time as a single value.
• DATEDIFF (X, Y): The function determines how much time has passed since two dates.
• CONCAT (X, Y): The function to add two string values to make a single string output.

7) How can MySQL be interacted with?

Three main ways to interact with MySQL are: 

• Using a command line, using a GUI, or both.
• Through a website.
• Through a language for writing code.

8) How do you create a database in MySQL?

To create a new database called "books," use the following command:

CREATE DATABASE books;

9) How does indexing in MySQL work?

Through the process of indexing, an unsorted list is transformed into an ordered list. It helps make table searches in MySQL more efficient. MySQL indexing serves similar purposes as a book index.

10) Who is MySQL under?

MySQL, distributed under the General Public License, is the most widely used free database management system. In its early stages, it was owned and maintained by MySQL. The database is now managed and developed by Oracle Corporation, which was formerly known as Sun Microsystems.

11) What is the default size of the MySQL database?

Mysql's myd files have a default size of 256 TB, and their pointer sizes are set to 6 bytes each.

12) What amount of memory does MySQL need?

With the default settings, a MySQL server can be run on a virtual machine with about 512MB of RAM. Increasing the values of a few system variables that deal with caches and buffers can improve MySQL's performance.

13) How many rows of data can MySQL store?

MySQL row sizes are limited to a maximum of 65,535 bytes, as demonstrated by the following examples using the InnoDB and MyISAM storage engines. The limit is consistently enforced, irrespective of the storage engine, even if the storage engine is capable of supporting rows that are larger than the limit.

14) What language does MySQL use to write its code?

Structured Query Language is more commonly known as SQL. The most popular standardized language used to access databases is SQL. Drubel, a web application, uses the MYSQL database system.

Related Article: Steps To Set-Up Your MySQL Reporting

15) What are MySQL's technical requirements?

These are MySQL's technical requirements:

• Manageability and Usability
• Flexible architecture
• High accessibility and replication
• Drivers
• MySQL Enterprise Manager
• JSON Compatibility
• High Availability and Replication
• Controlling storage and security
• Transactions and OLTP
• High performance that is easy to use and manage
• MySQL Enterprise Protection
• Graphical Instruments
• Geo-Spatial Assistance

MySQL Interview Questions For Experienced

16) What is the difference between SQL and MySQL?

• Generally speaking, SQL is the query language of choice. It functions similarly to MySQL as a database interface. MySQL is a secure database management system that can store various data types.
• You'll need a PHP script to enter data into the database and retrieve it later.
• MySQL is a database management system (DBMS), while SQL is a computer language.
• Information can be saved, deleted, and retrieved with the help of MySQL, which is a database management system, and SQL, which is used to create such systems.

17) What types of tables does MySQL support?

There are usually many tables. MyISAM, in contrast, is MySQL's native database engine. Five distinct types of tables are available:

• Heap Merge
• MyISAM
• ISAM INNO DB

18) How do I add a foreign key to my MySQL database?

A connection between two or more tables can be made using a "foreign key." This is accomplished by contrasting the value in the primary key field of one table with the value in the primary key field of another table. Because of the tables, we can create a relationship similar to that of a parent and a child. There are two different ways that a table can have a foreign key added to it:

Employing the CREATE TABLE Statement

Employing the "ALTER TABLE" Statement

19) How can a database be created in MySQL Workbench?

MySQL Workbench must be started and logged into with the appropriate credentials before a new database can be created. 

1. Select Schema from the Navigation menu. 
2. Choose Create Schema from the right-click menu or the database icon (red rectangle). 
3. As soon as we click the button, a new window will pop up where we can enter our information. 
4. To finish creating the database, click the Apply button after entering the necessary information.

20) How can data be deleted from a MySQL table?

With MySQL, the DELETE statement is used to delete rows from a table:

DELETE FROM table_name

WHERE column_name = value_name

Related Article: Import Excel into MySQL

21) In MySQL, how do you view a database?

With the following command, you can see all the databases on the MySQL server host:

mysql> SHOW DATABASES;

22) How do you add a user to MySQL?

Using the CREATE command and passing in the required information, you can create a new User. For instance:

CREATE USER 'testuser' IDENTIFIED BY 'sample password';

23) How can a column be deleted from a database?

If you want to delete a column from a database, use the DROP keyword.

ALTER TABLE classics DROP pages;

24) How does MySQL add columns?

In a table, a column is a group of cells with the same value for one row. With the ALTER TABLE statement, we can add columns to a table that already has them.

ALTER TABLE table_name     

ADD COLUMN column_name column_definition [FIRST|AFTER existing_column];

25) How do you execute and create views in MySQL?

To make a view, use the CREATE VIEW statement. This is a perfect example:

CREATE
   [OR REPLACE]
   [ALGORITHM = {MERGE | TEMPTABLE | UNDEFINED }]
   [DEFINER = { user | CURRENT_USER }]
   [SQL SECURITY { DEFINER | INVOKER }]
   VIEW view_name [(column_list)]
   AS select_statement
   [WITH [CASCADED | LOCAL] CHECK OPTION]

26) How can a table be updated in MySQL?

We can use the UPDATE statement, which consists of the SET clause and the WHERE clause, to modify records in a table already in the database. The values of the specified columns can be changed using the SET clause. The WHERE clause, which outlines the parameters of the condition, is not required. All data in a single row's columns can be updated with this statement, and it can do the same for multiple rows simultaneously.

27) What is MySQL's BLOB?

A large binary object, or BLOB for short, is a large binary data structure. The amount of information it stores can change. A BLOB can store massive amounts of information—such as written text, photographs, and motion pictures. The entire manuscript could be kept in a BLOB if that's what's required.

Different BLOB types are:

• TINY BLOB
• MEDIUMBLOB
• LONG BOB

28) In MySQL, what is a Stored Procedure?

A stored procedure is just a group of SQL statements saved in the database. The stored procedure may include one or more SQL statements (such as INSERT, UPDATE, or DELETE). A procedure facilitates code reuse by executing a single statement. The database is home to the data dictionary.

29) How do you execute a MySQL stored procedure?

A stored procedure can be executed with the help of MySQL's CALL query. The stored procedure's name and other parameters can be passed to this query.

30) How Do You Make a MySQL View?

A base table provides the values for a MySQL view database object. It makes a virtual table by joining one or more physical tables in a query. Despite lacking any data, it functions in a manner akin to the base table. Any modifications to the underlying table are updated in the view.

31) What are MySQL Transaction Storage Engines?

You need to use MySQL's InnoDB storage engine to use the transaction facility MySQL provides (which is the default from version 5.5 onward). If you are still determining which version of MySQL your code will be running on, rather than assuming that InnoDB is the default engine, you can force the use of InnoDB when you create a table. This is an alternative to the assumption that InnoDB is the default engine.

32) How do I set up a MySQL Trigger?

A database trigger is a section of procedural code that is automatically executed whenever particular events occur on a particular table or view. MySQL triggers can be created to respond to a variety of different conditions. It is possible to run it whenever new records are added to a table, or any columns in the table are modified.

33) How do I use MySQL to import a CSV file?

The comma-separated values (CSV) file can be imported into a MySQL table. If you want to save your data in a table format, you can export it as a comma-separated values (CSV) file. In MySQL, a CSV file can be imported using the LOAD DATA INFILE statement. Using this statement, you can quickly put information from a text file into a database table. Here is how to import a CSV file in its entirety:

LOAD DATA INFILE 'C:/ProgramData/MySQL/MySQL Server 8.0/Uploads/filename.csv'     

INTO TABLE tablename     

FIELDS TERMINATED BY ''    

OPTIONALLY ENCLOSED BY '" '    

LINES TERMINATED BY '\r\n.'     

IGNORE 1 ROWS;

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34) What is the difference between MyISAM Dynamic and MyISAM Static?

Every field in a MyISAM static table will have the same width setting. The Dynamic MyISAM table will have fields, such as TEXT and BLOB, to accommodate data types with varying lengths. In the event of database corruption, MyISAM Static would be simpler to restore.

Conclusion

Several free or low-cost database management systems include MySQL, PostgreSQL, and SQLite. Consider what is most important when comparing MySQL to other database systems. So, use these frequently asked MySQL Interview questions to learn more about the subject and help you prepare. So that you can learn something that will be helpful to score or crack the interview.