Doing CRUD with C# and SQL best ways do to do and display data

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SQL

C#5.0

Hello everybody,
I have a test coming up soon for a job that I have applied for. I have been working on having this so I have it all down and memorized so I know exactly what I am doing when it comes to the test.
I have to do CRUD in C# and MySQL. I was wondering if I could get some examples of the best ways I should do this. I will show what I have but I feel like there are better and more efficient ways of doing this, or actually an easier way. I have been struggling with bits and pieces but I would really like to see what people have as suggested for me.
I also have to display the data from the database on the program(listbox, grid, etc I can pick what control)
Example 1

public static bool UpdateActivity(Activity oldActivity,
Activity newActivity)
{
    SqlCeConnection connection = Connection.GetConnection();
    string updateStatement =
        "UPDATE Activities SET " +
        "ActivityName = @NewActivityName, " +
        "Calories = @NewCalories " +
        "WHERE ActivityName = @OldActivityName " +
        "AND Calories = @OldCalories ";
    SqlCeCommand updateCommand =
        new SqlCeCommand(updateStatement, connection);
    updateCommand.Parameters.AddWithValue(
        "@NewActivityName", newActivity.ActivityName);
    updateCommand.Parameters.AddWithValue(
        "@NewCalories", newActivity.Calories);
    updateCommand.Parameters.AddWithValue(
        "@OldActivityName", oldActivity.ActivityName);
    updateCommand.Parameters.AddWithValue(
        "@OldCalories", oldActivity.Calories);
    try
    {
        connection.Open();
        int count = updateCommand.ExecuteNonQuery();
        if (count > 0)
            return true;
        else
            return false;
    }
    catch (SqlCeException ex)
    {
        throw ex;
    }
    finally
    {
        connection.Close();
    }
}

public static int AddActivity(Activity activity)
{
    SqlCeConnection connection = Connection.GetConnection();
    string insertStatement =
        "INSERT Activities " +
        "(ActivityName, Calories) " +
        "VALUES (@ActivityName, @Calories)";
    SqlCeCommand insertCommand =
        new SqlCeCommand(insertStatement, connection);
    insertCommand.Parameters.AddWithValue(
        "@ActivityName", activity.ActivityName);
    insertCommand.Parameters.AddWithValue(
        "@Calories", activity.Calories);
    try
    {
        connection.Open();
        insertCommand.ExecuteNonQuery();
        //return IDENT_CURR(client.ClientID);
        return activity.ActivityID;
    }
    catch (SqlCeException ex)
    {
        throw ex;
    }
    finally
    {
        connection.Close();
    }
}

public static List<Activity> GetActivities()
{
    List<Activity> activities = new List<Activity>();
    SqlCeConnection connection = Connection.GetConnection();
    string selectStatement = "SELECT * " +
                             "FROM Activities ";
    SqlCeCommand selectCommand =
        new SqlCeCommand(selectStatement, connection);
    try
    {
        connection.Open();
        SqlCeDataReader activityReader = selectCommand.ExecuteReader();
        while (activityReader.Read())
        {
            Activity activity = new Activity();
            activity.ActivityID = (int)activityReader["ActivityID"];
            activity.ActivityName = activityReader["ActivityName"].ToString();
            activities.Add(activity);

        }
        activityReader.Close();
    }
    catch (SqlCeException ex)
    {
        throw ex;
    }

    finally
    {
        connection.Close();
    }
    return activities;
}

public static bool DeleteActivity(Activity activity)
{
    SqlCeConnection connection = Connection.GetConnection();
    string deleteStatement =
        "DELETE FROM Activities " +
        "WHERE ActivityName = @ActivityName " +
        "AND Calories = @Calories " +
        "AND ActivityID = @ActivityID";
    SqlCeCommand deleteCommand =
        new SqlCeCommand(deleteStatement, connection);
    deleteCommand.Parameters.AddWithValue(
        "@ActivityName", activity.ActivityName);
    deleteCommand.Parameters.AddWithValue(
        "@Calories", activity.Calories);
    deleteCommand.Parameters.AddWithValue(
         "@ActivityID", activity.ActivityID);

    try
    {
        connection.Open();
        int count = deleteCommand.ExecuteNonQuery();
        if (count > 0)
            return true;
        else
            return false;
    }
    catch (SqlCeException ex)
    {
        throw ex;
    }
    finally
    {
        connection.Close();
    }
}


public static Activity GetActivity(String ActivityName)
{
    SqlCeConnection connection = Connection.GetConnection();
    string selectStatement
        = "SELECT ActivityName, ActivityID, Calories "
        + "FROM Activities "
        + "WHERE ActivityName = @ActivityName";
    SqlCeCommand selectCommand =
        new SqlCeCommand(selectStatement, connection);
    selectCommand.Parameters.AddWithValue("@ActivityName", ActivityName);

    try
    {
        connection.Open();
        SqlCeDataReader activityReader =
            selectCommand.ExecuteReader(CommandBehavior.SingleRow);
        if (activityReader.Read())
        {
            Activity activity = new Activity();
            activity.ActivityName = activityReader["ActivityName"].ToString();
            activity.ActivityID = (int)activityReader["ActivityID"];
            activity.Calories = (int)activityReader["Calories"];
            return activity;
        }
        else
        {
            return null;
        }
    }
    catch (SqlCeException ex)
    {
        throw ex;
    }
    finally
    {
        connection.Close();
    }
}

Example 2

public static string connectionString = @"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\crudDB.mdf;Integrated Security=True";


public static void CreateUser(User user)
{
    SqlConnection connect = new SqlConnection(connectionString);
    string CreateStatement = "INSERT INTO [dbo].[Users](userName, userType) VALUES(@userName, @userType)";
    SqlCommand createCmd = new SqlCommand(CreateStatement, connect);
    createCmd.Parameters.AddWithValue("@userName", user.UserName);
    createCmd.Parameters.AddWithValue("@userType", user.UserType);
    try
    {
        connect.Open();
        createCmd.ExecuteNonQuery();
        //return user.UserID;
    }
    catch (SqlException sql) { MessageBox.Show(sql.Message.ToString()); }
    catch (Exception ex) { MessageBox.Show(ex.Message.ToString()); }
    finally
    {
        connect.Close();
    }
}
private void btnClick_Click(object sender, EventArgs e)
{
    SqlConnection connect = new SqlConnection(connectionString);
    string name = txtName.Text;
    string age = txtAge.Text;
    using(connect)
    {
        SqlCommand cmd = new SqlCommand("INSERT INTO [dbo].[people](Name, Age) VALUES(@Name, @Age)", connect);
        cmd.Parameters.AddWithValue("@Name", txtName.Text);
        cmd.Parameters.AddWithValue("@Age", txtAge.Text);
        connect.Open();
        cmd.ExecuteNonQuery();
        connect.Close();
    }
}