Operating mysql knowledge in Python (2)

1. Create a table Teacher in mysql:

create table Teacher(
	teaId int not null,
	teaname varchar(100),
	age int,
	sex enum('M', 'F'),
	phone int);

Notice:

    Difference between char and varchar:

    ‘123’    ------>varchar(10)       #  3位

    '123 ' -------> char(10) # 10 digits, less than 10 digits are filled with spaces

2. Create a super user:

grant all privileges on *.* to 'fxq'@'%' identified by '123456' with grant option;

3. Data query:

select *  from Teacher where id >20

select * from Teacher where id in(10,20,30)

select * from Teacher where id like ('%1001%')

 Query duplicate data:

select *  from Teacher where group by teaname having count(*) >1;

Joint query:

select * from a,c where a.id = c.组id

View the table structure:

show create table_name
desc table_name 

4. Insert data:

insert into table_name(id,name,age) values(1,'feng',20);

Insert multiple rows of data:

insert into table_name(id,name,age) values(1,'feng',20),(2,'zhang',30),(3,'wang',40);

5. Delete data:

delete from table where 条件判断
truncate table_name;   #清空数据
drop table_name;   #删除表

6. Update data 

update table_name set  列名=XXXX,where 条件；

7. Create an index:

create index 库名_表名_列名1_列名2  （列名1，列名2）