Shulou(Shulou.com)06/01 Report--

Basic Operation of Mysql based on linux operating system (3)

Knowledge point 1: view all users in MYSQL database

Command: select distinct concat ('User:''',user,'''@''',host,''';') as query from mysql.user

Note: (1) the keyword DISTINCT is used to return a unique different value.

Syntax: SELECT DISTINCT column name FROM table name

(2) the SQL CONCAT function is used to concatenate two strings to form a single string.

Compare the usage of the two:

Knowledge point 2: view the permissions of a specific user in the database

(1) Command: show grants for 'cacti'@'127.0.0.1'

The screenshot is as follows:

(2) Command: select * from mysql.user where user='cacti'\ G

The screenshot is as follows:

Knowledge point 3: to view the user table structure, specific items can be queried in combination with the table structure.

Command: desc mysql.user

The screenshot is as follows:

Knowledge point 4: delete users

Command: delete from mysql.user where user='cacti'and host='127.0.0.1'\ G

The screenshot is as follows:

Note: mysql > flush privileges; (refresh database)

Mysql > drop database testDB; / / Delete the user's database

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