Search function fail - asp.net

Question

I would like to search data in a textbox . Below is my code. I tried to search but nothing happen.
If Not Me.IsPostBack Then
Me.SearchPanelId()
End If
End Sub
Private Sub SearchPanelId()
Dim ConnectionString As String = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString
Using con As New SqlConnection(ConnectionString)
Using cmd As New SqlCommand()
Dim sql As String = "SELECT panelid, panelname, paneltype FROM PANEL_TABLE"
If Not String.IsNullOrEmpty(TextBox1.Text.Trim()) Then
sql += " WHERE panelid LIKE #panelid + '%'"
cmd.Parameters.AddWithValue("#panelid", TextBox1.Text.Trim())
End If
cmd.CommandText = sql
cmd.Connection = con
Using sda As New SqlDataAdapter(cmd)
Dim dt As New DataTable()
sda.Fill(dt)
GridView1.DataSource = dt
GridView1.DataBind()
End Using
End Using
End Using
End Sub
Protected Sub Search(sender As Object, e As EventArgs)
Me.SearchPanelId()
End Sub
Protected Sub OnPaging(sender As Object, e As GridViewPageEventArgs)
GridView1.PageIndex = e.NewPageIndex
Me.SearchPanelId()
End Sub

Answer 1

Do the validation before you start creating objects. You need to check if that datatype of the ID is valid. I guessed that this was an Integer type but check your database. If I am wrong and the datatype is .VarChar then see the second rendition. :-) The Like keyword does not make any sense with a numeric field.
Don't use .AddWithValue See http://www.dbdelta.com/addwithvalue-is-evil/
and
https://blogs.msmvps.com/jcoehoorn/blog/2014/05/12/can-we-stop-using-addwithvalue-already/
and another one:
https://dba.stackexchange.com/questions/195937/addwithvalue-performance-and-plan-cache-implications
A DataAdapter is not necessary. Just use the load method of the DataTable.
Private Sub SearchPanelId()
Dim IDValue As Integer
Dim dt As New DataTable
If String.IsNullOrEmpty(TextBox1.Text.Trim()) OrElse Not Integer.TryParse(TextBox1.Text.Trim, IDValue) Then
Return
End If
Using con As New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
Using cmd As New SqlCommand("SELECT panelid, panelname, paneltype FROM PANEL_TABLE WHERE panelid = #panelid", con)
cmd.Parameters.Add("#panelid", SqlDbType.Int).Value = IDValue
con.Open()
dt.Load(cmd.ExecuteReader)
End Using
End Using
GridView1.DataSource = dt
GridView1.DataBind()
End Sub
If Id is a .VarChar
Private Sub SearchPanelId()
Dim dt As New DataTable
If String.IsNullOrEmpty(TextBox1.Text.Trim()) Then
Return
End If
Using con As New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
Using cmd As New SqlCommand("SELECT panelid, panelname, paneltype FROM PANEL_TABLE WHERE panelid Like #panelid", con)
cmd.Parameters.Add("#panelid", SqlDbType.VarChar).Value = TextBox1.Text.Trim() & "%"
con.Open()
dt.Load(cmd.ExecuteReader)
End Using
End Using
GridView1.DataSource = dt
GridView1.DataBind()
End Sub