Programming/MySQL

Installation

Ubuntu

Basic installation can be performed with:

 sudo apt install mysql-server 

From here, you can access MySQL via:

 sudo mysql 

Securing the Installation

Note that the above command alone is an insecure installation, and is not suitable for things like production, or instances where stored data is not just test data and thus should be stored securely.

To configure MySQL for security also run:

 sudo mysql_secure_installation 

The MySQL Shell

You can access the MySQL server from a terminal via the MySQL shell.

If you have a fresh install with no setup yet, then this is likely done via sudo mysql.

If you have done some setup, such as setting a password for the root account or creating a user to login with, then use mysql -u <username> -p.

User Accounts

Connecting as Root

Warn: Note that this is not recommended for any instances when the database should be secure. Use this only for development and testing instances, where security of data does not matter.

For previous versions of MySQL, it was standard to default the root user as a login user with a password of root. This is no longer the default, but can easily be set with a few commands. First, enter the MySQL shell. Then enter:

 ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'root'; 

• This will set the root user's password to "root".
• Alternatively, alter the password to whatever you desire, if you want to add a tiny bit more security (setting root as a login-able password user is still not very recommended for security reasons).

 FLUSH PRIVILEGES; 

• This ensures that changes will propagate through the server without a reboot.

Once set, the sudo mysql command will likely no longer work. Instead, login with root as mysql -u root -p.

Adding a New User Account

Add a new user account with:

 CREATE USER '<username>'@'localhost' IDENTIFIED BY '<password>'; 

Where <username> and <password> are replaced by the desired username and password for the user account.

User Permissions

Once created, a user account needs to be given permission in order to be useful at all. Note that, from a security standpoint, it's always best to give the minimum possible permissions necessary for the user to do their job.

Full Permissions

Warn: Note that this is not recommended for any instances when the database should be secure. Use this only for development and testing instances, where security of data does not matter.

To give a user full permissions (like the root account), launch the MySQL Shell, then run:

 GRANT ALL PRIVILEGES ON *.* TO '<username>'@'localhost' WITH GRANT OPTION; 

• Where username is replaced by the name of the user account to adjust.

 FLUSH PRIVILEGES; 

• This ensures that changes will propagate through the server without a reboot.

Databases

MySQL splits things up into individual "databases". Generally speaking, each database is a cohesive, separate project.

Creating a New Database

From the MySQL Shell:

 CREATE DATABASE <database_name>; 

• Where <database_name> is replaced by the desired name for the database. Must be unique from all other existing databases in the MySQL server.

To specify the database character set:

 CREATE DATABASE <database_name> DEFAULT CHARACTER SET utf8mb4 DEFAULT COLLATE utf8mb4_general_ci; 

Note that utf8mb4 is the preferred character set for most situations. See this link for details.

Loading a Database

From the MySQL Shell:

 USE <database_name>; 

• Where <database_name> is replaced by the name of database you wish to select/load.
• Note that only one database can be selected/loaded at a time.

Deleting a Database

From the MySQL Shell:

 DROP DATABASE <database_name>; 

• Where <database_name> is replaced by the name of the database to delete. Note that this action cannot be undone.

Database Commands

The following commands will apply to whatever database is currently selected/loaded. Template:ToDo