need help for sql server 2005

ok first, Foreign keys do not really 'join' tables, they rather 'relate' tables and the main reason why it is useful to create foreign key constraint in a table is serve as a checking mechanism to prevent actions that will cause data in a related table through an action like dropping a table etc

Below is a basic sql code showing a table with a foreign key cons.

CREATE TABLE Orders
(
O_Id int NOT NULL,
OrderNo int NOT NULL,
P_Id int,
PRIMARY KEY (O_Id),
FOREIGN KEY (P_Id) REFERENCES Persons(P_Id)
)

but in joining two tables (in a sort of extension), then you would have to use sql joins, which if you dont have any knowledge of yet, I would edge you to do google it up and read..Also check up the sql union..:)

Hi Ridhi Shrestha,

follow the below links

http://www.1keydata.com/sql/sql-foreign-key.html

http://www.mssqlcity.com/Articles/General/using_constraints.htm


Table CUSTOMER
column name characteristic
------------ ------------
SID int Primary Key
Last_Name varchar(50)
First_Name varchar(50)

Table ORDERS

CREATE TABLE ORDERS
(Order_ID integer primary key,
Order_Date datetime,
Customer_SID int references CUSTOMER(SID),
Amount money)


Cheers :)