my foreign key is giving null values

Sindhu Kavuri

8y869

hii,

here i had referred ID as a foreign key which is the primary key of another table.

see i will show you my tables

mood table.

CREATE TABLE tblmood(

moodid INT PRIMARY KEY IDENTITY(1,1) ,

mood VARCHAR(30) NOT NULL,

ID INT FOREIGN KEY REFERENCES signup(ID)

);

Signup table

CREATE TABLE signup(

ID INT PRIMARY KEY IDENTITY(1,1) ,

username VARCHAR(30) NOT NULL,

email VARCHAR(30) NOT NULL,

passwd VARCHAR(30) NOT NULL,

);

so , whats the problem is in the mood table i am getting the null , instead the user id from the signup table

Someone show me the right direction .

Thanks in Advance

9 Replies

Know the answer? Post it — somebody with the same question will find it here.

Nitin Sontakke8y ago
Accepted answer
Aha!

Use following script to create a table. Because you definitely not expecting to enter a row in tblMood table without the singup id. Right?
CREATE TABLE tblMood
(
moodid INT PRIMARY KEY IDENTITY(1,1) ,
mood VARCHAR(30) NOT NULL,
ID INT not null FOREIGN KEY REFERENCES signup(ID)
);
If you use you will start getting errors. So I am deliberately asking you make this change.
I already saw your code in another question you had asked here. And I notice that you are ONLY inserting mood and NOT inserting Signup ID at all.
Nitin Sontakke8y ago
You mention that this is an ASP.NET code. When an user logs in, you will of course need to store user's id in session where it is persisted. And use that Id whenever you need it.

Remember ASP.NET session is a huge subject by itself, in which, I am not going here. Use it as much MINIMUM as you can.
Sindhu Kavuri8y ago
Greetings @Nitin Sontakke

if i am making that column not null i am getting error in my asp.net code
because iam not inserting any data into the ID column throug tblmood ,
i am auto generating ID in signup table when the user register , so after the same user login and select the mood and then submit , i want his ID from the signup table to enter in the tblmood table .

But i dont how it should be done.

Thank you so much for your help.
Nitin Sontakke8y ago
It doesn't matter. It is identical and it will still work. Make column not null and make sure you are inserting value in your db code. It should work as expected.

Should you have any more question / issues / queries / doubts, please DO NOT hesitate to get in touch. Happy to help, as always!

Sindhu Kavuri8y ago

person tables

PersonID	LastName	FirstName	Age
1	Hansen	Ola	30
2	Svendson	Tove	23
3	Pettersen	Kari	20

and order table

OrderID	OrderNumber	PersonID
1	77895	3
2	44678	3
3	22456	2
4	24562	1

i want something like this

Sindhu Kavuri8y ago
Actually by using asp.net i am inserting data into the tables
thats it other than that i am not doing anything
Sindhu Kavuri8y ago
ID username passwd

1 sindhu 14008

2 sama 14006

3 hari 14009

4 rani 14007

THE ABOVE IS MY SIGNUP TABLE

THIS IS MY tblmood

moodid mood ID

1happy NULL

2sad NULL

3angry NULL

4angry NULL

5angry NULL

6angry NULL

7angry NULL

8angry NULL

Here in the ID i need the id number from the signup table
Nitin Sontakke8y ago
I just hope you are querying as follows:
select *
from signup s
left outer join tblMood m on s.[Id] = m.[Id]
Piyush Pansuriya8y ago
Hi, Can you share your query and Data?