Basic operations of MySQL data table, addition, deletion and modification & DML

MySql Basic operation -DML

DML explain

DML It refers to the data operation language , The full English name is (Data Manipulation Language), Used to add data records of tables in the database 、 Delete 、 modify .

keyword ：

• insert Insert
• update to update
• delete Delete

Insert data into insert

Grammar format ：

​ insert into surface ( Column 1, Column 2, Column 3, …) values ( value 1, value 2, value 3, …); // Insert values... Into the table , Must match type

​ insert into surface values ( value 1, value 2, value 3, …); // Insert values for all columns

Example ：

​ insert into student (sid, name, gender, age, birth, address) values (1, ‘oscar’, ‘man’, 18, ‘2010-12-12’, ‘ Longgang District, Shenzhen ’);

Data update update

Grammar format ：

​ update Table name set Field name = value , Field name = value

Example ：

# There are no conditions , Then all addresses of the whole table will be changed to Shenzhen 
update student set address = ' Shenzhen '

# With query criteria , Only specified conditions take effect 
update student set address = ' Shenzhen ' where id = 1

# You can update the values of multiple fields at the same time  , Separated by commas 
update student set address = ' Shenzhen ', name = 'litchi' where id = 1

Data deletion delete

Grammar format

​ delete form Table name [where Conditions ]

​ truncate table Table name perhaps truncate Table name

Example ：

--  Delete sid by 1 The data of 
delete form student where sid = 1
--  Delete all data from the table 
delete from student;
--  Empty data 
truncate table student;
truncate student;

delete Is to delete all data in the table , and truncate Is equivalent to deleting the table and then rebuilding the table data structure , More thorough .

summary

DML Data manipulation language , Mainly aimed at MySql Add, delete and change

Three basic operations ：

insert

delete

update