Account management, database building and four engines + cases of MySQL

1、 Find the database engine

show engines;

2、 Create database

#create database Database name

create database text;
# Complete writing
create database if not exists text default charset utf8 collate utf8_general_ci;

3、 Lookup database

show databases;

5、 Account management

#5.1、 Create user and set password
create user zking identified by '123456';

#5.2、 Switching users
use mysql;

#5.3、 View user information
#192.168.1.%  ipv4  ipv6
select * from user;
select host,user,authentication_String from user;

4、 Delete database （ Divine user , Recommended disable ;）

drop user zking;

 6 Change Password

set password for zking=password('1234');

 7 Refresh configuration

flush privileges;

 8 to grant authorization （grant）

# grammar ：grant all [pricilenges] on databasename.tablename to user name @'%'
#garnt all on *.* to [email protected]'%';
grant select,delete on t277.t_book to [email protected]'%';

9 Withdrawal of power （revoke）

# grammar ：revoke all [privileges] on dataasename.tablename from user name @'%';
#revoke all on *.* from [email protected]'%';
revoke select on t277.t_book from [email protected]'%';

10 Query authority

show grants for zking;

Here is a case

#decimal(5,2)
# Five in total , Integer bits, three bits , Two decimal places 
create table if not exists t_money(
	id int not null primary key auto_increment,
	money decimal(5,2)
);

select * from t_money;

create table t_student(
	sid int not null primary key auto_increment comment ' Student number ',
	sname varchar(20) not null comment ' The student's name ',
	idcard varchar(18) not null comment ' ID number ',
	sex char(1) default '1' comment ' Student gender ,1= male ,0= Woman ',
	createdate timestamp default current_timestamp comment ' Date of creation ',
	unique(sname,idcard)
)comment ' Student information sheet ';

create table t_score(
	sid int not null comment ' Student number ',
	cid int not null comment ' Course number ',
	score float default 0 comment ' achievement ',
	foreign key(sid) references t_student(sid)
)comment ' Student transcript ';

# Delete the appearance first , Delete the main table 
insert into t_score(sid,cid,score) values(1,2,90.5);
select * from t_student;
select * from t_score;

This is today's sharing ！