Database connection and data saving in SQL Server - database

Question

I have SQL SERVER database file in Project folder. The same file copy in Debug folder. I attach these two files in SQL Server. File in project folder table contains Null value in all field. But there is data in the file attached from the Debug folder. I created the connection string with the file in Project folder. Actually which database file is the correct file? Try to solve this problem.
The Connection String is
Public Conn As SqlConnection
Public Function getConnect() As SqlConnection
Conn = New SqlConnection("Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\EMP_DB.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True")
Return Conn
End Function
And this is my code..
Try
getConnect()
Dim query As SqlCommand
Dim strSQL As String
strSQL = "INSERT INTO EMPLOYEE (EMP_ID,EMP_NAME,EMP_FNAME,EMP_GENDER,EMP_DOB,EMP_CAST,EMP_DEPART,EMP_DESIG,EMP_DOJ,EMP_SALARY,EMP_PF_ESI,EMP_BRANCH,EMP_CONTACT,EMP_ADDRESS)VALUES(#EMP_ID,#EMP_NAME,#EMP_FNAME,#EMP_GENDER,#EMP_DOB,#EMP_CAST,#EMP_DEPART,#EMP_DESIG,#EMP_DOJ,#EMP_SALARY,#EMP_PF_ESI,#EMP_BRANCH,#EMP_CONTACT,#EMP_ADDRESS)"
query = New SqlCommand(strSQL, Conn)
query.Parameters.Add(New SqlParameter("#EMP_ID", TXTEMPID.Text))
query.Parameters.Add(New SqlParameter("#EMP_NAME", TXTNAME.Text))
query.Parameters.Add(New SqlParameter("#EMP_FNAME", TXTFNAME.Text))
query.Parameters.Add(New SqlParameter("#EMP_GENDER", gend))
query.Parameters.Add(New SqlParameter("#EMP_DOB", DTPEMPDOB.Value.Date))
query.Parameters.Add(New SqlParameter("#EMP_CAST", TXTCASTE.Text))
query.Parameters.Add(New SqlParameter("#EMP_DEPART", CMBDEPT.Text))
query.Parameters.Add(New SqlParameter("#EMP_DESIG", CMBDESIG.Text))
query.Parameters.Add(New SqlParameter("#EMP_DOJ", DTPEMPDOJ.Value.Date))
query.Parameters.Add(New SqlParameter("#EMP_SALARY", MTXTSAL.Text))
query.Parameters.Add(New SqlParameter("#EMP_PF_ESI", MTXTPFESI.Text))
query.Parameters.Add(New SqlParameter("#EMP_BRANCH", TXTBRANCH.Text))
query.Parameters.Add(New SqlParameter("#EMP_CONTACT", MTXTCONTACT.Text))
query.Parameters.Add(New SqlParameter("#EMP_ADDRESS", RTXTADDRESS.Text))
Conn.Open()
Dim numAffected = query.ExecuteNonQuery()
'MessageBox.Show(numAffected)
Conn.Close()
If numAffected > 0 Then
Call getConnect()
MessageBox.Show("Successfully Added", "Add", MessageBoxButtons.OK, MessageBoxIcon.Information)
BTNCLEAR.PerformClick()
Else
MsgBox("No record was inserted")
End If
Catch ex As Exception
MsgBox("ERROR: " + ex.Message, MsgBoxStyle.Information, "Add")
End Try
End If
I change my connection string like this...
Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\EMP_DB.mdf;Initial Catalog=EMP_DB;Integrated Security=True;Connect Timeout=30;User Instance=False

Answer 1

User instances are depreciated, and probably what is causing this confusion.
To quote SQL Server MVP Aaron Bertrand:
Using User Instance means that SQL Server is creating a special copy
of that database file for use by your program. If you have two
different programs using that same connection string, they get two
entirely different copies of the database. This leads to a lot of
confusion, as people will test updating data with their program, then
connect to a different copy of their database in Management Studio,
and complain that their update isn't working. This sends them through
a flawed series of wild goose chase steps trying to troubleshoot the
wrong problem.
[Source]
He also goes on to list some alternatives in the same post:
Create or attach your database to a real instance of SQL Server. Your connection string will then just need to specify the instance name, the database name, and credentials. There will be no mixup as Management Studio, Visual Studio and your program(s) will all be connecting to a single copy of the database.
If you're using SQL Server 2012, use SqlLocalDb for local development. See: "Getting Started with SQL Server 2012 Express LocalDB."
Use SQL Server Compact. I like this option the least because the functionality and syntax is not the same - so it's not necessarily going to provide you with all the functionality you're ultimately going to want to deploy.