Summary: In this chapter, we will learn how to manage databases in MySQL like: create new databases, remove existing databases, and show all databases in the MySQL server.
How to Manage Database in MySQL
Let’s start creating a new database in MySQL.
Creating new Database
Before doing anything else with the data, you need to create a database. A database is a container of data. It stores any kind of data that you can think of. In MySQL, a database is a collection of objects that are used to store and manipulate data such as tables, database views, triggers, stored procedures, etc.
To create a database in MySQL, we use the CREATE DATABASE statement as follows:
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| CREATE DATABASE [IF NOT EXISTS] database_name; |
Let’s examine the CREATE DATABASE statement in greater detail:
- Followed by the CREATE DATABASE statement is database name that you want to create. It is recommended that the database name should be as meaningful and descriptive as possible.
- The IF NOT EXISTS is an optional clause of the statement. The IF NOT EXISTS clause prevents you from an error of creating a new database that already exists in the database server. You cannot have 2 databases with the same name in a MySQL database server.
For example, to create test_database, you can execute the CREATE DATABASE statement as follows:
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| CREATE DATABASE test_database; |
After executing this statement, MySQL returns a message to notify that the new database has been created successfully or not.
Displaying list of Database
The SHOW DATABASES statement displays all databases in the MySQL database server. we can use the SHOW DATABASES statement to check the database that we’ve created or to see all the databases on the database server before you create a new database, for example:
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| SHOW DATABASES; |
We have four databases in the MySQL database server. The information_schema and mysql are the default databases that are available when we install MySQL, and the test_database is the new database that we have created.
Selecting database to work
Before working with a particular database, you must tell MySQL which database you want to work with by using the
USE statement.
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| USE database_name; |
You can select any database to work with you want. Here we’ll select test_database sample database using the USE statement as follows:
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| USE test_database ; |
From now all operations such as querying data, create new tables or calling stored procedures which you perform, will take effects on the current database i.e., company.
Removing Databases
Removing database means you delete the database physically. All the data and associated objects inside the database are permanently deleted and this cannot be undone. Therefore, it is very important to execute this query with extra cautions.
To delete a database, you use the DROP DATABASE statement as follows:
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| DROP DATABASE database_name; |
Followed the DROP DATABASE is the database name that you want to remove.
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| DROP DATABASE test_database; |
If you want to practice with the DROP DATABASE statement, you can create a new database, make sure that it is created, and remove it.
In this chapter, we have learnt various statements to manage databases in MySQL including creating a new database, removing an existing database, selecting a database to work with, and displaying all databases in a MySQL database server.
MySQL DELETE MySQL Table Types
MySQL DELETE MySQL Table Types
