"The ConnectionString property has not been initialized" error in VB.NET
40,171
Solution 1
You never assigned your connection string to the connection object, just like the error is saying.
Insert a line setting the connection string before con.open.
Con.connectionstring = connection
Con.Open()
Or better yet, change your using statement as follows
Dim Connection As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=G:\VB Project\Library Catalog System\Library Catalog System\library.mdf;Integrated
Security=True;Connect Timeout=30;User Instance=True"
Using Con As New SqlConnection(connection)
Solution 2
You are creating the connection string object but never assigning it to your SqlCommand
object.
Author by
CompleteNewb
Updated on July 09, 2022Comments
-
CompleteNewb almost 2 years
Every time I tried to connect to the database it give me this error "The ConnectionString property has not been initialized"
what can I do to solve this?
here are my codes
Module Module1 Function GetInfoForStudent(ByRef QueryName As String, ByVal UserName As String, ByVal Password As String) As DataTable Using Con As New SqlConnection Try Using OleCon As New SqlConnection Dim Connection As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=G:\VB Project\Library Catalog System\Library Catalog System\library.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True" Con.Open() Dim Cmd As SqlCommand = Con.CreateCommand() Cmd.CommandType = CommandType.StoredProcedure Cmd.CommandText = QueryName Cmd.Parameters.AddWithValue("@user", UserName) Cmd.Parameters.AddWithValue("@pass", Password) Dim da As New SqlDataAdapter(Cmd) Dim ds As New DataTable() da.Fill(ds) Return ds End Using Catch ex As Exception Throw New Exception(ex.Message) End Try End Using End Function End Module Sub ShowStudentInfo() Dim dt As DataTable = GetInfoForStudent("MyStoredProcName", "@user", "@pass") ' Since (presumably) only one is returned With dt.Rows(0) ' Assign your text boxes StudentIDTextBox.Text = .Item("StudentID") LoginIDTextBox.Text = .Item("LoginID") Student_NameTextBox.Text = .Item("Student Name") Student_addressTextBox.Text = .Item("Student address") End With End Sub