What’s wrong with that method?

Question

I’m creating an Asp net mvc application, I created a domain class with:

    public class Parcela
        {
            public int parcelaId { get; set; }

            public decimal valor { get; set; }

            public DateTime vencimento { get; set; }

            public string status { get; set; }

            public virtual int clienteId { get; set; }

            public int numero { get; set; }
        }

Then I created a method in my library class:

public class ParcelaBLL
    {
        //metodo abaixo para listar todos os clientes na tabela 
        public IEnumerable<Parcela> GetParcelas()
        {
            string connectionString = ConfigurationManager.ConnectionStrings["ConSQLServer"].ConnectionString;
            List<Parcela> parcelas = new List<Parcela>();
            try
            {
                using (SqlConnection con = new SqlConnection(connectionString))
                {
                    var query = "Select parcelaId, clienteId, valor, vencimento, status, numero FROM Parcelas";
                    SqlCommand cmd = new SqlCommand(query, con);
                    cmd.CommandType = CommandType.Text;
                    con.Open();
                    SqlDataReader rdr = cmd.ExecuteReader();
                    while (rdr.Read())
                    {
                        Parcela parcela = new Parcela();
                        parcela.parcelaId = Convert.ToInt32(rdr["parcelaId"]);
                        parcela.clienteId = Convert.ToInt32(rdr["clienteId"]);
                        parcela.valor = Convert.ToDecimal(rdr["valor"]);
                        parcela.vencimento = Convert.ToDateTime(rdr["vencimento"]);
                        parcela.status = rdr["status"].ToString();
                        parcela.numero = Convert.ToInt32(rdr["numero"]);
                    }
                }
                return parcelas;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
    }

And here in my index view should be displaying the data of each table field that is saved in the database:

@model IEnumerable<BLL.Models.Parcela>

@{
    ViewBag.Title = "Index";
}

<h2>Index</h2>

<p>
    @Html.ActionLink("Adicionar nova parcela", "Create")
</p>
<table class="table" border="1">
    <tr>
        <th>
            @Html.DisplayNameFor(model => model.clienteId)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.numero)
        </th>
        <th>
             @Html.DisplayNameFor(model => model.status)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.vencimento)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.valor)
        </th>
        <th></th>
    </tr>

@foreach (var item in Model)
{
    using (@Html.BeginForm("Deletar", "Parcelas", new { id = item.parcelaId }))
    {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.valor)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.vencimento)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.status)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.clienteId)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.numero)
        </td>
        <td>
            @Html.ActionLink("Editar", "Edit", new { id = item.parcelaId }) |
            @Html.ActionLink("Detalhes", "Details", new { id = item.parcelaId }) |
            @Html.ActionLink("Deletar", "Delete", new { id = item.parcelaId })
        </td>
    </tr>
    }
}

</table>

Am I doing something wrong? Could someone help me with this??