Hi Honeyjo,

Refer below stored procedure.

CREATE PROCEDURE [dbo].[usp_GetRecordbySurnamePMRefStatus] 
(
	@LastName nvarchar(50) = NULL,
	@PMRef nvarchar(50) = NULL,
	@RecordStatus nvarchar(100) = NULL
) 
AS 
BEGIN
	SET NOCOUNT ON; 
	SELECT *
	FROM [dbo].[Autopsybook]
	Where (LastName = @LastName OR @LastName IS NULL) 
	AND (PMRef = @PMRef OR @PMRef IS NULL) 
	AND (ecordStatus = @RecordStatus OR @RecordStatus IS NULL)
END 
GO

Code

Protected Sub btnsearch_OnClick(sender As Object, e As EventArgs) Handles btnsearch.Click    
	Using con As SqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("conString").ConnectionString)
		Using cmd As SqlCommand = New SqlCommand("usp_GetRecordbySurnamePMRefStatus", con)
			cmd.CommandType = CommandType.StoredProcedure
			If Not String.IsNullOrEmpty(txtsearch.Text.Trim()) Then
				cmd.Parameters.AddWithValue("@LastName", txtsearch.Text.Trim())
			Else
				command.Parameters.AddWithValue("@LastName", DBNull.Value)
			End If
			If ddlGridfilter.SelectedItem.Value > 0 Then
				cmd.Parameters.AddWithValue("@PMRef", ddlGridfilter.SelectedItem.Text)
			Else
				command.Parameters.AddWithValue("@PMRef", DBNull.Value)
			End If
			If ddlstatussearch.SelectedItem.Value > 0 Then
				cmd.Parameters.AddWithValue("@RecordStatus", ddlstatussearch.SelectedItem.Text)
			Else
				command.Parameters.AddWithValue("@RecordStatus", DBNull.Value)
			End If
			Using sda As SqlDataAdapter = New SqlDataAdapter(cmd)
				Dim dt As DataTable = New DataTable()
				sda.Fill(dt)
				Me.gvEmployee.DataSource = dt
				Me.gvEmployee.DataBind()
			End Using
		End Using
	End Using
End Sub

For more details refer below link.

Filter GridView based on multiple CheckBoxList like Flipkart in ASP.Net

Hello Sir,

Thank you so much for your help.

I have used the Stored Procedure and the code. The status is working fine. 

Stored Procedure is working fine for all three fields, but the vb code is not returning any values for the M number and the Surname.  I have added the VB below. 

Please advice. 

Many Thanks

        Using con As SqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("Database_Connection_Lookups").ConnectionString)
            Using cmd As SqlCommand = New SqlCommand("usp_GetRecordbySurnamePMRefStatus", con)
                cmd.CommandType = CommandType.StoredProcedure
                If Not String.IsNullOrEmpty(txtsearch.Text.Trim()) Then
                    cmd.Parameters.AddWithValue("@LastName", txtsearch.Text.Trim())
                Else
                    cmd.Parameters.AddWithValue("@LastName", DBNull.Value)
                End If
                If Not String.IsNullOrEmpty(txtsearch.Text.Trim()) Then
                    cmd.Parameters.AddWithValue("@PMRef", txtsearch.Text.Trim())
                Else
                    cmd.Parameters.AddWithValue("@PMRef", DBNull.Value)
                End If
                If ddlstatussearch.SelectedItem.Value <> "" Then
                    cmd.Parameters.AddWithValue("@RecordStatus", ddlstatussearch.SelectedItem.Text)
                Else
                    cmd.Parameters.AddWithValue("@RecordStatus", DBNull.Value)
                End If
                Using sda As SqlDataAdapter = New SqlDataAdapter(cmd)
                    Dim dt As DataTable = New DataTable()
                    sda.Fill(dt)
                    Me.GridView1.DataSource = dt
                    Me.GridView1.DataBind()
                End Using
            End Using
        End Using