1.新建用户
//登录MYSQL
#mysql -u root -p
#密码
//创建用户
mysql> insert into mysql.user(Host,User,Password) values(‘localhost’,'lwd',password('lwd'));
//刷新系统权限表
mysql>flush privileges;
这样就创建了一个名为:lwd 密码为:lwd 的用户。
//退出后登录一下
mysql>exit;
#mysql -u lwd -p
#输入密码
mysql>登录成功
2.为用户授权
//登录MYSQL(有ROOT权限)。我里我以ROOT身份登录。
#mysql -u root -p
#密码
//首先为用户创建一个数据库(lwdDB)
mysql>create database lwdDB;
//授权lwd用户拥有lwd数据库的所有权限
#grant all privileges on lwdDB.* to lwd@localhost identifiedby 'lwd';
//刷新系统权限表
mysql>flush privileges;
mysql>其它操作
//如果想指定部分权限给一用户,可以这样来写:
mysql>grant select,update on lwdDB.* to lwd@localhost identifiedby 'lwd';
//刷新系统权限表。
mysql>flush privileges;
mysql> grant权限1,权限2,…权限n on 数据库名称。表名称 to用户名@用户地址 identified by ‘连接口令’;
权限1,权限2,…权限n代表select,insert,update,delete,create,drop,index,alter,grant,references,reload,shutdown,process,file等14个权限。
当权限1,权限2,…权限n被all privileges或者all代替,表示赋予用户全部权限。
当数据库名称。表名称被*.*代替,表示赋予用户操作服务器上所有数据库所有表的权限。
用户地址可以是localhost,也可以是ip地址、机器名字、域名。也可以用’%’表示从任何地址连接。
‘连接口令’不能为空,否则创建失败。
例如:
mysql>grant select,insert,update,delete,create,drop onvtdc.employee to lwd@10.163.225.87 identified by ‘123′;
给来自10.163.225.87的用户lwd分配可对数据库vtdc的employee表进行select,insert,update,delete,create,drop等操作的权限,并设定口令为123。
mysql>grant all privileges on vtdc.* to lwd@10.10.10.87 identifiedby ‘123′;
给来自10.163.225.87的用户lwd分配可对数据库vtdc所有表进行所有操作的权限,并设定口令为123。
mysql>grant all privileges on *.* to lwd@10.10.10.87 identifiedby ‘123′;
给来自10.163.225.87的用户lwd分配可对所有数据库的所有表进行所有操作的权限,并设定口令为123。
mysql>grant all privileges on *.* to lwd@localhost identifiedby ‘123′;
给本机用户lwd分配可对所有数据库的所有表进行所有操作的权限,并设定口令为123。
3.删除用户
#mysql -u root -p
#密码
mysql>DELETE FROM user WHERE User=”lwd” and Host=”localhost”;
mysql>flush privileges;
//删除用户的数据库
mysql>drop database lwdDB;
4.修改指定用户密码
#mysql -u root -p
#密码
mysql>update mysql.user set password=password(‘新密码’) whereUser=”lwd” and Host=”localhost”;
mysql>flush privileges;
mysql>quit;

InnoDBBufferPool reduces disk I/O by caching data and indexing pages, improving database performance. Its working principle includes: 1. Data reading: Read data from BufferPool; 2. Data writing: After modifying the data, write to BufferPool and refresh it to disk regularly; 3. Cache management: Use the LRU algorithm to manage cache pages; 4. Reading mechanism: Load adjacent data pages in advance. By sizing the BufferPool and using multiple instances, database performance can be optimized.

Compared with other programming languages, MySQL is mainly used to store and manage data, while other languages such as Python, Java, and C are used for logical processing and application development. MySQL is known for its high performance, scalability and cross-platform support, suitable for data management needs, while other languages have advantages in their respective fields such as data analytics, enterprise applications, and system programming.

MySQL is worth learning because it is a powerful open source database management system suitable for data storage, management and analysis. 1) MySQL is a relational database that uses SQL to operate data and is suitable for structured data management. 2) The SQL language is the key to interacting with MySQL and supports CRUD operations. 3) The working principle of MySQL includes client/server architecture, storage engine and query optimizer. 4) Basic usage includes creating databases and tables, and advanced usage involves joining tables using JOIN. 5) Common errors include syntax errors and permission issues, and debugging skills include checking syntax and using EXPLAIN commands. 6) Performance optimization involves the use of indexes, optimization of SQL statements and regular maintenance of databases.

MySQL is suitable for beginners to learn database skills. 1. Install MySQL server and client tools. 2. Understand basic SQL queries, such as SELECT. 3. Master data operations: create tables, insert, update, and delete data. 4. Learn advanced skills: subquery and window functions. 5. Debugging and optimization: Check syntax, use indexes, avoid SELECT*, and use LIMIT.

MySQL efficiently manages structured data through table structure and SQL query, and implements inter-table relationships through foreign keys. 1. Define the data format and type when creating a table. 2. Use foreign keys to establish relationships between tables. 3. Improve performance through indexing and query optimization. 4. Regularly backup and monitor databases to ensure data security and performance optimization.

MySQL is an open source relational database management system that is widely used in Web development. Its key features include: 1. Supports multiple storage engines, such as InnoDB and MyISAM, suitable for different scenarios; 2. Provides master-slave replication functions to facilitate load balancing and data backup; 3. Improve query efficiency through query optimization and index use.

SQL is used to interact with MySQL database to realize data addition, deletion, modification, inspection and database design. 1) SQL performs data operations through SELECT, INSERT, UPDATE, DELETE statements; 2) Use CREATE, ALTER, DROP statements for database design and management; 3) Complex queries and data analysis are implemented through SQL to improve business decision-making efficiency.

The basic operations of MySQL include creating databases, tables, and using SQL to perform CRUD operations on data. 1. Create a database: CREATEDATABASEmy_first_db; 2. Create a table: CREATETABLEbooks(idINTAUTO_INCREMENTPRIMARYKEY, titleVARCHAR(100)NOTNULL, authorVARCHAR(100)NOTNULL, published_yearINT); 3. Insert data: INSERTINTObooks(title, author, published_year)VA


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

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

SublimeText3 English version
Recommended: Win version, supports code prompts!

SublimeText3 Chinese version
Chinese version, very easy to use

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software