MySQL command statement (personal summary)

1 Add sentences

1.1 Add information to the list

insert into table_name(list_name,list_name......) values('values1','values2'.......),('values1','values2'........);

1.2 Add column to table

The operation of adding columns is similar to the following line of code , among table_name Is the table name you want to modify ,last_name Is the column name you want to add ,varchar(10) You can change it to the data type and value range you want .

alter table table_name add last_name varchar(10);

2 Delete statements

2.1 Delete the specified column

alter table table_name drop last_name;

2.2 Delete the specified information

( Delete one or more records )

2.2.1 Delete the entire list

delete from table_name;

2.2.2 Delete a record

delete from table_name where list_name='values';

2.3 Clear data in table

delete from table_name;

truncate table table_name;

3 Modify the information

3.1 Modify database code

In the following code database_name Is the name of the database you want to set ,gb2312 You can replace it with your own encoding format

alter database database_name character set gb2312;

3.2 Modify the value type or range of a table column

The modification method is the same as the above examples

alter table table_name modify list_name varchar(10);

3.3 Modify the name of the table

now_name Current table name
new_name Modified table name

rename table now_name to new_name;

3.4 Modify the character set encoding format of the table to utf-8

alter table table_name character set utf-8;

3.5 Change column names

alter table table_name change column name list_name varchar(100);

3.6 Modify the record

The first line of code simply modifies the data
The second line can add or subtract data on the original basis

update table_name set list_name=values,list_name=values where list_name=values;
update table_name set list_name=value+1000 where list_name=value;

4 Export import database

== Get into cmd ==

4.1 Export database （sql Script ）

mysqldump -u user name -p Database name > Exported file name

　mysqldump -u root -p db_name > test_db.sql

4.2 mysql Export a database table

mysqldump -u user name -p Database name Table name > Exported file name

mysqldump -u wcnc -p test_db users> test_users.sql （ There is no semicolon at the end ）

4.3 mysql Import database

source  File directory / name .sql

5 Query information

5.1 Query table structure

desc table_name;