MySQL database and the use of some common commands

Summary of COMMON commands:

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create database name;  Creating a database use databasename;  selecting a database drop database name;  Delete the database directly, do not remind show tables;  display table describe tablename;  table detailed description select  plus distinct remove duplicate fields   Show current MySQL version and current date select version (),current_date;  Modify the password for root in MySQL: shell>mysql -u root  -pmysql> update user set password=password ("Root123″)  where user= ' root ' ; mysql> flush privileges   Refresh Permissions mysql>use dbname;  Open the database mysql>show  databases;  Show all Databases mysql>show tables;  show all tables in MySQL database mysql>desc user;  Display column information for the user table in the MySQL database  grant create a Hyper-pipe account that can be connected from anywhere to the server and must be assigned a password mysql> grant all  privileges on *.* to  ' user_name ' @ ' localhost '  identified by   ' password '  ; format:grant select on  Database .* to  user name @ Login host  identified by  password   Delete Authorization: Mysql> revoke alL privileges on *.* from [email protected] "%"; mysql> delete from  user where user= "root"  and host= "%";mysql> flush privileges;  Rename table: mysql > alter table t1 rename t2;  Backup: mysqldump -hhostname - uusername -ppassword databasename > backup.sql;  Recovery: mysql -hhostname - uusername -ppassword databasename< backup.sql;

Here are two typical cases where MySQL 5.6 and MySQL 5.7 Install differences when initializing data. MySQL 5.6: When initializing the data, you need to go to the script directory of the home directory

Perform:

12	/usr/local/mysql/scripts/mysql_install_db--basedir=/usr/local/mysql/--datadir=/data/mysql--defaults-file=/etc/ MY.CNF--user=mysql

The database password is empty at this time. MySQL 5.7: When initializing the data, it needs to be executed in the bin directory of the home directory:

12	/usr/local/mysql/bin/mysqld--user=mysql--datadir=/data/mysql--basedir=/usr/local/mysql/--initialize

The operation to initialize the data using the mysql_install_db command has already been discarded. Note:--initialize will automatically generate a password in error log. If the plus--initialize-insecure password is empty

Use of MySQL database and some common commands