How to avoid to not add new row in DB , When i Edit User's

Man Down

I have page , where i can Edit User's Email and Password not problem ,but there is problem, when its send Data to Database , it will add new row everytime , when i just trying to edit User's Email, so how can i avoid that to not add new row in database , just send data in same row with out adding new row.

The code i have in my Action:

public ActionResult UserEdit(string Email)
{
return View(new user {Email = Email });
}
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult UserEdit(user User)
{
var db = new DataContext();
var u = db.PX.Where(t => t.Email_ID == User.Email).FirstOrDefault();
if (u == null)
db.PX.Add(new A_S_PX { Email_ID = User.Email, PS = User.Password });
else {
u.PS = User.Password;
u.Email_ID = User.Email;
}
db.SaveChanges();
return View(new user { Email = User.Email });
}

10 Replies

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

Man Down8y ago
@Rupesh
Thx Rupesh i will take look and i will back to you if there is something :) thx for ur help and ur time :)
+1
Rupesh Kahane8y ago
If you want to add PK then first delete old one
alter table Persion drop CONSTRAINT
then add new PK. May be your column will get added in last
ALTER TABLE dbo.YourTable
ADD ID INT IDENTITY
CONSTRAINT PK_YourTable PRIMARY KEY CLUSTERED
Refer my article
1) http://www.c-sharpcorner.com/article/crud-operation-using-repository-unit-of-work-pattern/

Other reference
1) http://www.c-sharpcorner.com/UploadFile/4b0136/database-first-approach-in-mvc-5-part-2/
+2
Man Down8y ago
@ Rupesh :

Im using MVC5 with EF
+1
Rupesh Kahane8y ago
How Email id can be a PK.

As per my info. Their is a Seperate PK per table used (In genearal depends upon requirement & as per architecture suggestion we used PK)

I will suggest add PK with Integer/Decimal datatype into your table & do the changes accordingly.

Note: It is depends upon the technologies used in project as well.

Let us know which technologies you are used like MVC with EF or any other, which approach you have used to create a database.

Thanks
+2
Man Down8y ago
@Nitin:

its SQL - Server
and
in my table , No column's have Primary key and sorry for last comment i mentioned Email_ID have Primary key , but its not.
and
in table i have Email_ID data type string and Password data type nvarchar
+1
Man Down8y ago
Thx Rupesh ,
I can use your answer , when i have Id as primary key , but right i dont have , is just question how can i add primary key in my existing table :)
+1
Nitin Sontakke8y ago
Which database system is this? You never mentioned. Please specify. Answer changes depending on that.

Whatever system is that does it already have a primary key defined as email address?

Please share as much details as you can, helps us help you better.
+2
Man Down8y ago
Yes sir , you right , i was forget to think about this part . Email_ID have key and therefor it can not be changed.

I hope its ok with you if i ask one more question ,so how can i add one more coulmn for ex Id , data type int and set that column as Primary key in my existing table !

thx
+1
Rupesh Kahane8y ago
1. var count = db.PX.Where(a => a.Id == User.Id).Count();
2. if (count != 0 && count != null)
3. {
4. u.Id= User.Id;
5. u.Password= User.Password;
6. u.Email = User.Email;
7. // update this entry to db
8. }
9. else
10. {
11. // add new record code here
12. }
Do a small correction as above
+2

Nitin Sontakke8y ago

The principle is really very simple, whatever is the key value, never allow user to change it. If you want / expect that some data element changes, DO NOT make it a key value.

No system ever will allow you change the the primary key with which it identifies you. If it does, it means, they have some different column which holds primary key and it is not exposed to you.

Now the ultimate decision is yours.

You may wish to first identify the user on the basis of email id, etc., fetch it's primary key value, preserve it, modify email id and use Primary key column while saving. Primary key column NEVER changes.