Service:

# chkconfig --list        list all system services
# chkconfig --list | grep on     List all started system services

# chkconfig --list mysqld

# whereis mysql  View the file installation path
# which mysql     Query the path of the running file (folder address)
usr/bin/mysql refers to: the running path of mysql
var/lib/mysql refers to: the storage path of the mysql database file
usr/lib/mysql refers to: the installation path of mysql

Add environment variables:

# vi/etc/profile
# export MYSQL_HOME=/usr/local/mysql
# export PATH=$PATH:$MYSQL_HOME/bin

1.Database instructions:

# service mysqld start    Start MySQL
# service mysqld restart Restart MySQL
# service mysqld stop     Stop MySQL

2.Enter MySQL form operation

# -u root -p /mysql -h localhost -u root -p DatabaseName;    enter MySQL
 MySQL> show databases;            list databases
 MySQL>  create database XXX;      create database XXX

 MySQL>  use databaseName;         use database databaseName
 MySQL>  show tables;              list forms

MySQL> create table mytablename (ID int auto_increment not null primary key,usename varchar(20),password varchar(64),sex varchar(10),address varchar(20));  create form
MySQL> drop table mytablename ;                 delete form
MySQL> drop database databasename;              delete database

3.Add, delete, modify, and check

MySQL>  insert into mytablename values('','zhangsan','123456','fomale','guiyanag');  insert

MySQL> select * from mytablename ;                 find verification results
MySQL> select * from mytablename  where ID = '1';  precise search

MySQL> update mytablename  set address ='shanghai' where username ='zhangsan'; modify zhangsan's address to shanghai

MySQL> delete from mytablename  where ID = '1';     delete record

New universal user

  grant select On database.* to username@localhost identity by'password'


The username user_1 and the password is 123456

The user can log in to the database from any PC

MySQL> grant select,insert update,delete on *.* to user_1@"%" identity by "123456";


Create a user who can only operate the database on this machine

The username user_2 and the password is 123456

MySQL> grant select,insert update,delete on *.* to user_2@localhost identity by "123456";

Log in to the database

MySQL> -u user_1 -p -h IP address;


In addition, I will list some commonly used commands for reference only:

Other mysql database related operations are as follows

(1) Create database TestDB mysql> create database TestDB;
(2) Make TestDB database the current default database mysql> use TestDB;
(3) Create table customers mysql in TestDB database> create table customers(userid int not null, username varchar(20) not null);
(4) Show database list mysql> show databases;
(5) Show the tables in the database mysql> show tables;
(6)Delete table customers mysql> drop table customers;
(7) Display the structure of the customers table mysql> desc customers;
(8) Insert a record into the customers table mysql> insert into customers(userid, username) values(1,'hujiahui');
(9) Let the operation take effect in time; mysql> commit;
(10) Query records in customers mysql> select * from customers;
(11) Update the data in the table mysql> update customers set username='DennisHu' where userid=1;
(12) Delete records in the table mysql> delete from customers;
(13) Grant likui users permission to access the database # grant select, insert, update, delete on *.* to likui@localhost indentified by "123456";