Mysql-related Common commands

1: A table has multiple primary keys.

Composite primary key

Create Table SC

(Studentno int, courseid int, score int, primary key (studentno, courseid ));

2: Use Chinese storage in the database

Create Database 'Article' default Character Set utf8 collate utf8_general_ci;

 

3: A good tutorial on SQL statements

Http://www.w3school.com.cn/ SQL/SQL _alter.asp

 

4. Modify Table content

Update class set c_year = "2011" where c_id = 1;

5. delete a row

Delete from test where t_id = "1 ";

6: Pretty good. MySQL functions commonly used in PHP

Http://www.php.net/manual/zh/ref.mysql.php

7. Set Foreign keys in the table

Create Table notice_ziliao (z_id varchar (20) primary key, z_date varchar (20), z_name varchar (128), z_t_id varchar (40), foreign key (z_t_id) references teacher (t_id ));

In the foreign key (z_t_id), do not add double quotation marks or quotation marks. Otherwise, a syntax error is returned.