C# Form Not Inserting Values Into Sql Server Database

I have a simple create a new user form which takes values from two text boxes, username and password. The button2 click event should take these values and insert them into the User

Solution 1:

The whole User Instance and AttachDbFileName= approach is flawed - at best! When running your app in Visual Studio, it will be copying around the .mdf file (from your App_Data directory to the output directory - typically .\bin\debug - where you app runs) and most likely, your INSERT 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 myConnection.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. DebenhamsProjectOfficeDatabase)

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=DebenhamsProjectOfficeDatabase;Integrated Security=True

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

Also: you should always use parametrized queries and not concatenate together your SQL statements (especially not when user input is included!) to (a) avoid any danger of SQL injection attacks, and to (b) improve performance!

Solution 2:

You have to call Command.ExecuteNonQuery() in order to take the effect of insert statement.

try
{
      SqlCommandcommand=newSqlCommand(sqlquery, cn);
      command.Parameters.AddWithValue("Username", username);
      command.Parameters.AddWithValue("Password", password);
      command.ExecuteNonQuery();
      command.Parameters.Clear();
      MessageBox.Show("User Added");
}
catch (Exception ex)
{
      MessageBox.Show(ex.Message);
}