Example of defining foreign key

ysuryawanshi_mcs · Posted: Mon Apr 03, 2006 4:33 pm

could anybody givi me example of defining foreign key
suppose i hav 2 tables 1.employee 2. dept
emp(eno,ename)
dept(dno,dname)

now i want dno as foreign key in emp so how should i write this

appasi · New User Joined: 12 Dec 2005 Posts: 20 Location: Bangalore

Hi ysuryawanshi_mcs,

If you want dno as foreign key then dno colomn must be in emp table as primary key colomn ( not the same colomn but same type and length should be same).

Please correct me if i am wrong

Appasi

Mr.Niceguy · New User Joined: 16 Jun 2005 Posts: 63

Hi,

Create one more field (DNO) in emp table having same data type and length. Assign DNO(dept) as primary key and DNO(emp) as foreign key.

perez_a · New User Joined: 02 Feb 2006 Posts: 25 Location: Italy

HI ysuryawanshi_mcs,

CREATE TABLE DEPT (
DNO <SAME TYPE OF ENO>,
DNAME ,
CONSTRAINT
FK01 FOREIGN KEY (DNO)
REFERENCES EMP(ENO)
);

AND REMEMBER THAT ENO MUST BE PRIMARY KEY IN EMP.
HAVE A NICE DAY.

friend_prasad · New User Joined: 06 Jan 2006 Posts: 12

hi yogesh suryawanshi this is prasad kulkarni

how r u ?
what is going on ?
have u completed u r syllabus
the answer of u r query is that which is given by the last guy
some body perez try it .if u havenot understand then mail me on my mail id

thanks
prasad