


This article mainly introducesmysql5.7 Creating user authorizationDeletingThe method of user revoking authorization is very good and has reference value. Friends who need it can refer to it
1. Create user:
Command:
CREATE USER 'username'@'host' IDENTIFIED BY 'password';
Description: username - the username you will create, host - specify the On which host can the user log in? If it is a local user, localhost can be used. If you want the user to log in from any remote host, you can use the wildcard character %. password - the user's login password. The password can be empty. , if it is empty, the user can log in to the server without a password.
Example:
CREATE USER 'dog'@'localhost' IDENTIFIED BY 'password'; CREATE USER 'pig'@'192.168.1.100' IDENDIFIED BY 'password'; CREATE USER 'pig'@'192.168.1.%' IDENDIFIED BY 'password'; CREATE USER 'pig'@'%' IDENTIFIED BY 'password'; CREATE USER 'pig'@'%' IDENTIFIED BY ''; CREATE USER 'pig'@'%';
2, Authorization:
Command:
GRANT privileges ON databasename.tablename TO 'username'@'host'
Description: privileges - user’s operation permissions, such as SELECT, INSERT, UPDATE, etc. (see the end of this article for a detailed list). If you want to grant all permissions, then Use ALL.;databasename - database name, tablename - table name. If you want to grant the user corresponding operation permissions on all databases and tables, you can use * to indicate it, such as *.*.
Example:
GRANT SELECT, INSERT ON test.user TO 'pig'@'%'; GRANT ALL ON *.* TO 'pig'@'%';
Note: A user authorized with the above command cannot authorize other users. If you want the user to be able to authorize, use the following command:
GRANT privileges ON databasename.tablename TO 'username'@'host' WITH GRANT OPTION;
Permission information Tables with user, db, host, tables_priv and columns_priv are stored in MySQL database (that is, in a database named mysql).
Permission column Context
select Select_priv table
insert Insert_priv table
update Update_priv table
delete Delete_priv table
index Index_priv table
alter Alter_priv table
create Create_priv database, table or index
drop Drop_priv database or table
grant Grant_priv database or table
references References_priv database or table
reload Reload_priv server management
shutdown Shutdown_priv server management
process Process_priv server management
file File_priv file access on the server
3. Set and change user password
Command:
SET PASSWORD FOR 'username'@'host' = PASSWORD('newpassword');如果是当前登陆用户用 SET PASSWORD = PASSWORD("newpassword");
Example:
SET PASSWORD FOR 'pig'@'%' = PASSWORD("123456");
4. Revoke user permissions
Command:
REVOKE privilege ON databasename.tablename FROM 'username'@'host';
Description: privilege, databasename, tablename - same Authorization part.
Example:
REVOKE SELECT ON *.* FROM 'pig'@'%';
Note: If you authorize user 'pig'@'%' like this (or similar): GRANT SELECT ON test.user TO 'pig'@'%',
then using the REVOKE SELECT ON *.* FROM 'pig'@'%';
command cannot revoke the user's access to the user in the test database SELECT operation of the table. On the contrary, if the authorization is GRANT SELECT ON *.* TO 'pig'@'%';
then REVOKE SELECT ON test.user FROM 'pig'@'%
';The command cannot revoke the user's Select permission on the user table in the test database.
Detailed information can be viewed with the command SHOW GRANTS FOR 'pig'@'%';
.
##5. Delete user
Command:DROP USER 'username'@'host';
6 View user authorization
mysql> show grants for 'test01'@'localhost'; +--------------------------------------------------------------------------------------------------------------------------------------------+ | Grants for test01@localhost | +--------------------------------------------------------------------------------------------------------------+ | GRANT USAGE ON *.* TO 'test01'@'localhost' | | GRANT INSERT, UPDATE, DELETE, CREATE, DROP, REFERENCES, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, EVENT, TRIGGER ON `test001`.* TO 'test01'@'localhost' | +--------------------------------------------------------------------------------------------------------------------------------------------+ 2 rows in set (0.01 sec) mysql> show grants for 'test02'@'localhost'; +-------------------------------------------------------------+ | Grants for test02@localhost | +-------------------------------------------------------------+ | GRANT USAGE ON *.* TO 'test02'@'localhost' | | GRANT ALL PRIVILEGES ON `test001`.* TO 'test02'@'localhost' | +-------------------------------------------------------------+ 2 rows in set (0.00 sec)
The above is the detailed content of Detailed introduction to the sample code of mysql5.7 to create user authorization, delete user and revoke authorization. For more information, please follow other related articles on the PHP Chinese website!

The steps for upgrading MySQL database include: 1. Backup the database, 2. Stop the current MySQL service, 3. Install the new version of MySQL, 4. Start the new version of MySQL service, 5. Recover the database. Compatibility issues are required during the upgrade process, and advanced tools such as PerconaToolkit can be used for testing and optimization.

MySQL backup policies include logical backup, physical backup, incremental backup, replication-based backup, and cloud backup. 1. Logical backup uses mysqldump to export database structure and data, which is suitable for small databases and version migrations. 2. Physical backups are fast and comprehensive by copying data files, but require database consistency. 3. Incremental backup uses binary logging to record changes, which is suitable for large databases. 4. Replication-based backup reduces the impact on the production system by backing up from the server. 5. Cloud backups such as AmazonRDS provide automation solutions, but costs and control need to be considered. When selecting a policy, database size, downtime tolerance, recovery time, and recovery point goals should be considered.

MySQLclusteringenhancesdatabaserobustnessandscalabilitybydistributingdataacrossmultiplenodes.ItusestheNDBenginefordatareplicationandfaulttolerance,ensuringhighavailability.Setupinvolvesconfiguringmanagement,data,andSQLnodes,withcarefulmonitoringandpe

Optimizing database schema design in MySQL can improve performance through the following steps: 1. Index optimization: Create indexes on common query columns, balancing the overhead of query and inserting updates. 2. Table structure optimization: Reduce data redundancy through normalization or anti-normalization and improve access efficiency. 3. Data type selection: Use appropriate data types, such as INT instead of VARCHAR, to reduce storage space. 4. Partitioning and sub-table: For large data volumes, use partitioning and sub-table to disperse data to improve query and maintenance efficiency.

TooptimizeMySQLperformance,followthesesteps:1)Implementproperindexingtospeedupqueries,2)UseEXPLAINtoanalyzeandoptimizequeryperformance,3)Adjustserverconfigurationsettingslikeinnodb_buffer_pool_sizeandmax_connections,4)Usepartitioningforlargetablestoi

MySQL functions can be used for data processing and calculation. 1. Basic usage includes string processing, date calculation and mathematical operations. 2. Advanced usage involves combining multiple functions to implement complex operations. 3. Performance optimization requires avoiding the use of functions in the WHERE clause and using GROUPBY and temporary tables.

Efficient methods for batch inserting data in MySQL include: 1. Using INSERTINTO...VALUES syntax, 2. Using LOADDATAINFILE command, 3. Using transaction processing, 4. Adjust batch size, 5. Disable indexing, 6. Using INSERTIGNORE or INSERT...ONDUPLICATEKEYUPDATE, these methods can significantly improve database operation efficiency.

In MySQL, add fields using ALTERTABLEtable_nameADDCOLUMNnew_columnVARCHAR(255)AFTERexisting_column, delete fields using ALTERTABLEtable_nameDROPCOLUMNcolumn_to_drop. When adding fields, you need to specify a location to optimize query performance and data structure; before deleting fields, you need to confirm that the operation is irreversible; modifying table structure using online DDL, backup data, test environment, and low-load time periods is performance optimization and best practice.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

WebStorm Mac version
Useful JavaScript development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

Dreamweaver CS6
Visual web development tools

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
