25 Essential MySQL Commands Every Developer Should Know（mysql基本命令）
MySQL is an open-source relational database management system that is extremely popular with developers. It has become the go-to solution for many web applications, and knowing how to use MySQL properly is a valuable skill. If you’re a developer who works with databases, it’s important to be familiar with the basic MySQL commands. This article will cover 25 essential MySQL commands every developer should know.
Before we get started, it’s important to note that all of these commands are run in the MySQL command line interface (CLI). To open the CLI, type the following command:
`mysql –u username –p password`
Replace ‘username’ and ‘password’ with your username and password.
Now, let’s take a look at the 25 essential MySQL commands.
1. Create Database:
This command allows you to create a database.
`CREATE DATABASE database_name;`
2. Drop Database:
This command allows you to delete a database.
`DROP DATABASE database_name;`
3. Show Databases:
This command lets you view the list of existing databases.
`SHOW DATABASES;`
4. Select a Database:
This command allows you to select a particular database to work with.
`USE database_name;`
5. Create a Table:
This command lets you create a table within a database.
`CREATE TABLE table_name (column_name datatype, column_name datatype, …);`
6. Alter Table:
This command lets you modify an existing table.
`ALTER TABLE table_name MODIFY column_name datatype;`
7. Drop Table:
This command lets you delete an existing table.
`DROP TABLE table_name;`
8. Show Tables:
This command allows you to view the list of existing tables.
`SHOW TABLES;`
9. Insert Data:
This command lets you insert data into a table.
`INSERT INTO table_name (column_name, column_name, …) VALUES (value, value, …);`
10. Select Data:
This command lets you select data from a table.
`SELECT * FROM table_name;`
11. Update Data:
This command lets you update existing data in a table.
`UPDATE table_name SET column_name = value WHERE column_name = value;`
12. Delete Data:
This command lets you delete existing data from a table.
`DELETE FROM table_name WHERE column_name = value;`
13. Create a User:
This command lets you create a user with limited privileges.
`CREATE USER username@localhost IDENTIFIED BY ‘password’;`
14. Set User Privileges:
This command lets you assign specific privileges to a user.
`GRANT SELECT, UPDATE, DELETE ON database_name.* TO username@localhost;`
15. Drop User:
This command lets you delete a user.
`DROP USER username@localhost;`
16. Change User Password:
This command lets you change a user’s password.
`ALTER USER username@localhost IDENTIFIED BY ‘new_password’;`
17. Create Index:
This command lets you create an index on a table.
`CREATE INDEX index_name ON table_name (column_name);`
18. Drop Index:
This command lets you delete an index on a table.
`DROP INDEX index_name ON table_name;`
19. Create a View:
This command lets you create a view of data from multiple tables.
`CREATE VIEW view_name AS SELECT column_name, column_name FROM table_name WHERE condition;`
20. Drop View:
This command allows you to delete a view.
`DROP VIEW view_name;`
21. Show Columns:
This command lets you view the list of columns in a table.
`SHOW COLUMNS FROM table_name;`
22. Show Status:
This command lets you view the current status of the server.
`SHOW STATUS;`
23. Export Table:
This command lets you export a table to a CSV file.
`SELECT * FROM table_name INTO OUTFILE ‘file_name.csv’ FIELDS TERMINATED BY ‘,’ ENCLOSED BY ‘”‘ LINES TERMINATED BY ‘\n’;`
24. Backup Database:
This command allows you to backup a database.
`mysqldump -u username -p database_name > backup_file.sql`
25. Restore Database:
This command allows you to restore a database from the backup file.
`mysql -u username -p database_name
These are the 25 essential MySQL commands that all developers should know. Knowing how to use these commands will come in handy when working with databases and will make life much easier.
It’s important to keep in mind that this is just the tip of the iceberg, and there are a lot more MySQL commands out there. As you continue to work with MySQL, you will discover more commands that can help you even more.
