Basic statement of MySQL (1) - add, delete, modify and query

Preface

MySQL Because of its small size 、 Fast 、 Low total cost of ownership , Especially open source , Generally, the development of small and medium-sized websites and large-scale websites all choose MySQL As website database .
So I'm going to record several commonly used sentences here ;
Each statement only introduces how to operate , Then I will write a comprehensive .

Build table

--  Delete user surface 
drop table if exists user;
--  establish user surface 
create table user
(
    -- id  Primary key 
     id           int primary key auto_increment,
    --  full name 
    name   varchar(20),
    --  Gender 
    sex varchar(20),
    --  Age 
    age      int,
    --  mailbox 
    email  varchar(100)

   
);

We can go straight to Navicat for MySQL Click in the database and create a new query , Copy the above code and run .

After running, we will get an initial data table .

Next, let's perform some operations .

Add sentences

Format ：inser into Table name （ Field 1, Field 2, Field 3……）values（ value 1, value 2, value 3……）
Separated by commas , Each field corresponds one by one .
for example ：
insert into user (id,name,sex,age,email) values(null,' Zhang San ',' male ',21,'[email protected]')
Be careful , If the type is varchar Need to be enclosed in quotation marks
After performing

Delete

Basically, deletion statements are deleted according to conditions .
So format ：delete from Table name where Conditions
For example, according to id Delete ：
delete from user where id =3

modify

Basically, delete statements are also operated according to conditions , But also bring in the value to be modified .
So format ：update Table name set data where Conditions
For example, according to id modify name：
update user set name = ' Brother Qiang ' where id = 4 ;

Inquire about

ad locum , Only show query all
sentence ： select * from Table name
select * from user

Summary

Only one example of each operation is written here , There are many more , Write after you understand it thoroughly .