c# – 尝试恢复数据库中列的当前值时出错

在我的C#代码中,我尝试恢复该值

protected string RecoverAllowComent(string id)
{
    try
    {
        using(SqlConnection conexao = new SqlConnection(_conexao))
        {
            SqlCommand comando = new SqlCommand();
            comando.CommandText = "SELECT AllowComent FROM San_Blog WHERE Id = @Id";
            comando.Parameters.Add(new SqlParameter("@Id",id));
            comando.CommandType = CommandType.Text;
            comando.Connection = conexao;
            conexao.Open();
            comando.ExecuteNonQuery();

            SqlDataAdapter da = new SqlDataAdapter(comando);
            DataTable dt = new DataTable();
            da.Fill(dt);

            if (dt.Rows.Count > 0)
            {
                return dt.Rows[0].ItemArray[0].ToString();
            }
            else                    
                return "False";
         }
     }
     catch
     {
         return "False";
     }
}

但我得到了错误
将nvarchar值“1”转换为数据类型int时转换失败.