Programming/MySQL/Databases: Difference between revisions

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== Databases ==
{{ note | Unless otherwise specified, all commands from this section assumes you're in the [[MySQL#Basics | MySQL shell]]. }}
MySQL splits things up into individual "databases". Generally speaking, each database is a cohesive, separate project.


=== Creating a New Database ===
MySQL splits things up into individual "databases". Generally speaking, each database is a cohesive, separate entity.
From the MySQL Shell:
 
{{ bc | CREATE DATABASE <database_name>; }}
== General Commands ==
* Where {{ ic |<database_name>}} is replaced by the desired name for the database. Must be unique from all other existing databases in the MySQL server.
=== Create a New Database ===
CREATE DATABASE <database_name>;
 
==== Specifying Character Set ====
{{ note | The following command should only be used if the database has a different character set from the server's default set. To set the server's character set, see [[Programming/MySQL/Setup | MySQL Setup]]. }}
 
To both create and specify the database character set:
CREATE DATABASE <database_name> DEFAULT CHARACTER SET utf8mb4 DEFAULT COLLATE utf8mb4_general_ci;


To specify the database character set:
{{ bc | CREATE DATABASE <database_name> DEFAULT CHARACTER SET utf8mb4 DEFAULT COLLATE utf8mb4_general_ci; }}
Note that <code>utf8mb4</code> is the preferred character set for most situations. See [https://medium.com/@adamhooper/in-mysql-never-use-utf8-use-utf8mb4-11761243e434 this link] for details.
Note that <code>utf8mb4</code> is the preferred character set for most situations. See [https://medium.com/@adamhooper/in-mysql-never-use-utf8-use-utf8mb4-11761243e434 this link] for details.


=== Loading a Database ===
=== Load a Database ===
From the MySQL Shell:
USE <database_name>;
{{ bc | USE <database_name>; }}
 
* Where {{ ic |<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.
* Note that only one database can be selected/loaded at a time.
 
=== Delete a Database ===
{{ warn | Note that this action cannot be undone. }}
DROP DATABASE <database_name>;
 
== Database Backups ==
=== Export Database to File ===
mysqldump -u <username> -p <database_name> > <file_location>


=== Deleting a Database ===
=== Import Database from File ===
From the MySQL Shell:
mysql -u <username> -p <database_name> < <file_location>
{{ bc | DROP DATABASE <database_name>; }}
* Where {{ ic |<database_name>}} is replaced by the name of the database to delete. Note that this action cannot be undone.

Revision as of 06:40, 20 November 2020

Note: Unless otherwise specified, all commands from this section assumes you're in the MySQL shell.

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

General Commands

Create a New Database

CREATE DATABASE <database_name>;

Specifying Character Set

Note: The following command should only be used if the database has a different character set from the server's default set. To set the server's character set, see MySQL Setup.

To both create and 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.

Load a Database

USE <database_name>;

Note that only one database can be selected/loaded at a time.

Delete a Database

Warn: Note that this action cannot be undone.
DROP DATABASE <database_name>;

Database Backups

Export Database to File

mysqldump -u <username> -p <database_name> > <file_location>

Import Database from File

mysql -u <username> -p <database_name> < <file_location>