Returning all search results from a SQL database with 1 search

Question

I am trying to build a small "application" that uses checkboxes as a search method. It works fine when only 1 box is checked at a time, but when I am checking more than one box, then it shows result from the last checked box only. I have been trying to debug it and I can see the datasource get overriden for every encounter. Anyone that can help with a input on how to "store" the data and not update it on every "if" statement?

C#

private void UpdateBinding()
{
  wodListBox.DataSource = null;
  wodListBox.DataSource = Exercise;
  wodListBox.DisplayMember = "ExerciseID";
}

private void Checkboxes()
{
    DataAccess db = new DataAccess();

    if (BarBellCheckBox.Checked)
    {
        Exercise = db.GetExercise(BarBellCheckBox.Text);
    }
    if (WallBallCheckBox.Checked)
    {
        Exercise = db.GetExercise(WallBallCheckBox.Text);
    }
    if (KettleBellCheckBox.Checked)
    {
        Exercise = db.GetExercise(KettleBellCheckBox.Text);
    }
    if (BarCheckBox.Checked)
    {
        Exercise = db.GetExercise(BarCheckBox.Text);
    }

    UpdateBinding();
}

public class DataAccess
{
    public List<ExerciseModel> GetExercise(string ExerciseEquipment)
    {

        using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(Helper.CnnVal("WodDB")))
        {

            return connection.Query<ExerciseModel>("dbo.GetEquipmentType @ExerciseEquipment", new { ExerciseEquipment = ExerciseEquipment }).ToList();

        }
    }
}

T SQL

CREATE PROCEDURE [dbo].[GetEquipmentType]
@ExerciseEquipment nvarchar(50)

AS
BEGIN
    SELECT ExerciseName, ExerciseEquipment
    FROM dbo.ExerciseName
    INNER JOIN dbo.ExerciseEquipment
    ON dbo.ExerciseName.ExerciseID = dbo.ExerciseEquipment.ExerciseID
    WHERE ExerciseEquipment = @ExerciseEquipment
END

Answer 1

Quick: You are overriding the results in every if -Block.

---

So how to fix this?

Since your 'Exercise' is of the type a List<ExerciseModel> you could initialize it before your if statements like:

Exercise = new List<ExerciseModel>();

and later on within your if block just use AddRange()

Exercise.AddRange( db.GetExercise(BarBellCheckBox.Text) );