I can't understand why I can't connect with my SQL Server Express LocalDB. I keep getting in to trouble with my connection string. This is what I have tried:
Imports System.Data.OleDb
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim conString As String 'Connection string
Dim con As OleDbConnection 'Connecting to your database
Dim Command As OleDbCommand 'Query "What do you want in the database"
'conString = "PROVIDER=System.Data.SqlClient v4.0; Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\DatabaseInnlogging.mdf;Integrated Security=True"
'conString = "PROVIDER=SQLOLEDB; Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\DatabaseInnlogging.mdf;Integrated Security=True"
'conString = "PROVIDER=System.Data.SqlClient; Data Source=C:\Users\Bruker\source\repos\InnloggingFørsøkv1\InnloggingFørsøkv1\DatabaseInnlogging.mdf;Integrated Security=True"
'conString = "PROVIDER=Microsoft.Jet.OLEDB.4.0; Data Source=C:\Users\Bruker\source\repos\InnloggingFørsøkv1\InnloggingFørsøkv1\DatabaseInnlogging.mdf;Integrated Security=True"
'conString = "PROVIDER=System.Data.SqlClient v4.0; Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\DatabaseInnlogging.mdf;Integrated Security=True"
Try
con = New OleDbConnection(conString)
con.Open()
Command = New OleDbCommand("select * from LogInTable where UserID = ? and Password = ?", con)
Dim parm1 As OleDbParameter, parm2 As OleDbParameter
parm1 = Command.Parameters.Add("@UserID", OleDbType.VarChar)
parm2 = Command.Parameters.Add("@Password", OleDbType.VarChar)
parm1.Direction = ParameterDirection.Input
parm2.Direction = ParameterDirection.Input
parm1.Value = Me.TextBox1.Text
parm2.Value = Me.TextBox2.Text
Command.Connection.Open()
Dim reader As OleDbDataReader
If reader.Read = True Then
Me.DialogResult = DialogResult.OK
Else
MsgBox("Invalid UserID or Password")
End If
reader = Command.ExecuteReader
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
I have tried several connection strings, but none is working.
But with the number 4, I got error
Multiple-step OLE DB operation generated errors.check each OLE DB status value
The others results in an error:
provider not recognized
My other attempt was with SqlClient
:
Imports System.Data.SqlClient
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim myConn As SqlConnection
myConn = New SqlConnection("Initial Catalog=OutComes; Data Source=localhost;Integrated Security=SSPI;")
'"Data Source = (LocalDB) \ MSSQLLocalDB;AttachDbFilename=|DataDirectory|\DatabaseInnlogging.mdf;Integrated Security=True")
' "Data Source=localhost;Integrated Security=SSPI;")
'Create a Command object.
Dim myCmd As SqlCommand
myCmd = myConn.CreateCommand
myCmd.CommandText = "SELECT UserID, Password FROM LogInTable"
'Open the connection.
myConn.Open()
Dim results As String
Dim myReader As SqlDataReader
myReader = myCmd.ExecuteReader()
'Traverse the DataSet and Display in GUi for Example:
Do While myReader.Read()
results = results & myReader.GetString(0) & vbTab &
myReader.GetString(1) & vbLf
Loop
'Display results.
MsgBox(results)
' Close the reader and the database connection.
myReader.Close()
myConn.Close()
End Sub
My error here was:
System.Data.SqlClient.SqlException: 'A network-related or instance-specific error occurred while connecting to SQL Server. The server was not found or was not available. Verify that the instance name is correct and that SQL Server is configured to accept external connections. (provider: Named Pipes Provider, error: 40 - Unable to open a connection to SQL Server)
I have one table in my SQL Server database with two columns UserID
and password
.
I would be very grateful if someone could point me in the right direction here. I have read many post on the subject but cant seem to find where I go wrong. My main goal here is to connect with my database.
As you are new you can try some visual tools it can help you to see more clear, I suggest you to try this approach, it's a half way to your solution:
In your visual Studio:
Menu Tools
Connection to database
In the Dialog
Data Source:
Microsoft SQL Server (sqlClient)
Server Name:
****
you should find your server here, select it, Else that's mean you have problem with your server installation
Authentification:
Windows Authentification
as i see in your example your are not using SQL id so that's fine
Connection to database:
Select the Database that you already created, if nothing seen that's mean you didn't created or you don't have rights to access
Then Click in button Test Connection
if success then click OK
Then go to your ToolBox
Data
DataGridView
drop it in your form select data source: in bottom you will see + Add the data source
click on it
You will have a Dialog, choose Database
-> Dataset
-> choose you data connection you should see a line in the combobox with your server name \ your Database.dbo
Check in the checkbox "Show the connection string saved in the application"
you will see clearly your connection string
Next -> Next > check Tables
Finish
If you stuck in some part let me know to clarify you by an Edit
First of all, THANK YOU:), I got it to work. But I still have som questions. I started with a fresh project and made a local sqlDB with one table with two columbs "UserID" and "Password". I had one line in this table with "Admin" and "pass" I did not use the table designer or add a datasource.
I followed your description to the letter and copied my connectionstring under tool connect... That worked fine and I found the mdf file and was able to connect to it
Loaded the form with a datagrid and bound it to the datasource. It worked properly
Then I tried to connect to the DB under a new button manualy. I got this error message:
System.Data.SqlClient.SqlException:
'Cannot attach file 'C:\Users\Bruker\source\repos\Connect_v2\Connect_v2\bin\Debug\Database1.mdf'
as database 'OutComes
' because this file is already in use for database
'C:\USERS\BRUKER\SOURCE\REPOS\CONNECT_V2\CONNECT_V2\BIN\DEBUG\DATABASE1.MDF''
This was the class:
Imports System.Data.SqlClient
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'Database1DataSet.LogInTable' table. You can move, or remove it, as needed.
Me.LogInTableTableAdapter.Fill(Me.Database1DataSet.LogInTable)
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim myConn As SqlConnection
myConn = New SqlConnection("Initial Catalog=OutComes; Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;Connect Timeout=30")
'Create a Command object.
Dim myCmd As SqlCommand
myCmd = myConn.CreateCommand
myCmd.CommandText = "SELECT UserID, Password FROM LogInTable"
'Open the connection.
myConn.Open()
Dim results As String
Dim myReader As SqlDataReader
myReader = myCmd.ExecuteReader()
'Traverse the DataSet and Display in GUi for Example:
Do While myReader.Read()
results = results & myReader.GetString(0) & vbTab &
myReader.GetString(1) & vbLf
Loop
'Display results.
MsgBox(results)
' Close the reader and the database connection.
myReader.Close()
myConn.Close()
End Sub
I tried to comment out the load event and It connected with the DB manualy. It worked:)
Imports System.Data.SqlClient
Public Class Form1
'Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
' 'TODO: This line of code loads data into the 'Database1DataSet.LogInTable' table. You can move, or remove it, as needed.
' Me.LogInTableTableAdapter.Fill(Me.Database1DataSet.LogInTable)
'End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim myConn As SqlConnection
myConn = New SqlConnection("Initial Catalog=OutComes; Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;Connect Timeout=30")
'Create a Command object.
Dim myCmd As SqlCommand
myCmd = myConn.CreateCommand
myCmd.CommandText = "SELECT UserID, Password FROM LogInTable"
'Open the connection.
myConn.Open()
Dim results As String
Dim myReader As SqlDataReader
myReader = myCmd.ExecuteReader()
'Traverse the DataSet and Display in GUi for Example:
Do While myReader.Read()
results = results & myReader.GetString(0) & vbTab &
myReader.GetString(1) & vbLf
Loop
'Display results.
MsgBox(results)
' Close the reader and the database connection.
myReader.Close()
myConn.Close()
End Sub
End Class
This is great but I still wonder why I got the error message. Is it because the datagridview tableadapter holds a constanctly open connection to the DB. And is not possible to have multiple open connections at the same time?
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