Primary And Foreign KEy Help

[john666]

Hi Guys..

 

Im new in PHP and Mysql

1 have Two table 1.students 2nd classes

i want to Set Primary key and Foreign Key in student Table and want to use Join Query on both

Help me in that

student Fields

 

 

1..(sn)seriel number

2..std_name

3.std_father_name

3..std_roll_num

4..std_class

5..std_cell

6..std_address

7..std_dob

8..std_address

9..std_fee

 

table 2 classes fields

 

1.class_id

2.class_name

3.date_created

 

what will be Primary key and foreign key here and join query to retrieve record   using phpmyadmin need step by step guide thanks

 

[Barand]

+--------------+       +-------------------+
| class        |       | student           |
+--------------+       +-------------------+
| class_id (PK)|--+    | serial number (PK)|
| class_name   |  |    | std_name          |
| date_created |  |    | std_father_name   |
+--------------+  |    | std_roll_num      |
                  +---<| std_class     (FK)|
                       | std_cell          |
                       | std_address       |
                       | std_dob           |
                       | std_fee           |
                       +-------------------+

                       

The primary keys are the unique identifiers of each record.

Assuming std_class contains the id of the student's class then that would be a foreign key.

 

To query the table using a JOIN you would have a query like this

 

SELECT c.class_name, s.std_name, s.std_father_name
FROM student as s
    INNER JOIN class as c ON s.std_class = c.class_id
ORDER BY c.class_name

Note that you need InnoDB tables to define foreign key constraints.

 

You do not have to formally define a foreign key to use a field in a join.