C# winform How to filter combobox if the specific column is not null

Question

For example I have a Project Table:

ProjectID | ProjectName | EstimateStartDate | EstimateEndDate | ActaulStartDate | ActualEndDate |  
    1     |Liberty Green|    06-26-2017     |   06-30-2017    |    06-26-2017   |   08-30-2017  |
    2     |   Wharton   |    06-26-2017     |   06-30-2017    |       null      |   null        |

So basically I want that all the rows Where ActualStartDate and ActualEndDate are null to be show in the ComboBoxProjectName, and all the not null will not show anymore in the ComboBoxProjectName.

Answer 1

you can try select all the rows where ActualStartDate is null... and then set datasource combobox by datatable :

SqlConnection con = new SqlConnection("ConnectionString");
        try
        {
            if (con.State == ConnectionState.Closed) con.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.CommandText = "Select * from Project Table where ActaulStartDate is null and ActualEndDate is null";
            cmd.Connection = con;
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            da.Fill(dt);

            comboBox1.DataSource = dt;
            comboBox1.DisplayMember = "ProjectName";
            comboBox1.ValueMember = "ProjectID";
        }
        catch (Exception)
        {
            throw;
        }
        finally
        {
            if (con.State == ConnectionState.Open) con.Close();
        }