how to update table data in sql database

Question

I am using asp.net for my project , and I am using the following code , but its not working correctly

 SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=E:\\WEB_PROJECT\\App_Data\\ASPNETDB.MDF;Integrated Security=True;User Instance=True");
 SqlCommand cmd = new SqlCommand();
 cmd.Connection = con;
 con.Open();
 cmd.CommandText = "UPDATE info SET fname = @fn, lname = @fl, phone= @ph, recoveryq=@rq, recoverya=@ra WHERE username = @un";  

 cmd.Parameters.AddWithValue("fn", TextBox3.Text);
 cmd.Parameters.AddWithValue("fl", TextBox4.Text);
 cmd.Parameters.AddWithValue("ph", TextBox5.Text);
 cmd.Parameters.AddWithValue("rq",TextBox6.Text);
 cmd.Parameters.AddWithValue("ra",TextBox2.Text);
 cmd.Parameters.AddWithValue("un",line);        
 cmd.ExecuteNonQuery();
 con.Close();

Advice plzz i m confused !!! :(

Solution 1

As I've said before on this site - the whole User Instance and AttachDbFileName= approach is flawed - at best! Visual Studio will be copying around the .mdf file and most likely, your UPDATE works just fine - but you're just looking at the wrong .mdf file in the end!

If you want to stick with this approach, then try putting a breakpoint on the con.Close() call - and then inspect the .mdf file with SQL Server Mgmt Studio Express - I'm almost certain your data is there.

The real solution in my opinion would be to

1. install SQL Server Express (and you've already done that anyway)

2. install SQL Server Management Studio Express

3. create your database in SSMS Express, give it a logical name (e.g. ASPNETDB)

4. connect to it using its logical database name (given when you create it on the server) - and don't mess around with physical database files and user instances. In that case, your connection string would be something like:

   Data Source=.\\SQLEXPRESS;Database=ASPNETDB;Integrated Security=True
   

   and everything else is exactly the same as before...

Solution 2

cmd.Parameters.AddWithValue("@fn", TextBox3.Text);

You have to specify the parameter name along with '@' .

Comments

[El Ronnoco]

No one will be able to help you unless you explain why it's "not working". Please post the error you receive or explain in what way it is not doing what you want.

[KingCronus]

I'd be willing to guess that your update matches 0 rows

[Kamil Będkowski]

In my opinion the way You have chosen is a bit obsolete. Consider use some ORM (like Entity Framework). It makes Your developing much easier and faster.

[Admin]

put "@fn" similarly "@fl" for all your column name hope so it will help you

[Admin]

please try to mention the error that you got

[Adil Mammadov]

Have you tried cmd.BindByName=true??

[Eshant Sahu]

error is : Incorrect syntax near ','.

[Damith]

@ is not must, issue is something else