I was trying to run my database but this error appears. System.NullReferenceException: 'Object reference not set to an instance of an object.
with era null
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;
namespace Roger_Silva_DR2_AT.DAL
{
public class DataAccessLayer
{
public string InserirDados(Usuario objuser)
{
SqlConnection con = null;
string result = "";
try
{
con = new SqlConnection(ConfigurationManager.ConnectionStrings["mycon"].ToString());
SqlCommand cmd = new SqlCommand("Usp_InserirAtulizarDeletar_Usuario", con)
{
CommandType = CommandType.StoredProcedure
};
cmd.Parameters.AddWithValue("@ID", 0);
cmd.Parameters.AddWithValue("@Nome", objuser.Nome);
cmd.Parameters.AddWithValue("@Sobrenome", objuser.Sobrenome);
cmd.Parameters.AddWithValue("@Nascimento", objuser.Nascimento);
cmd.Parameters.AddWithValue("@Query", 1);
con.Open();
result = cmd.ExecuteScalar().ToString();
return result;
}
catch
{
return result = "";
}
finally
{
con.Close();
}
}
public string AtualizarDados(Usuario objuser)
{
SqlConnection con = null;
string result = "";
try
{
con = new SqlConnection(ConfigurationManager.ConnectionStrings["mycon"].ToString());
SqlCommand cmd = new SqlCommand("Usp_InserirAtualizarDeletar_Usuario", con)
{
CommandType = CommandType.StoredProcedure
};
cmd.Parameters.AddWithValue("@ID", objuser.ID);
cmd.Parameters.AddWithValue("@Nome", objuser.Nome);
cmd.Parameters.AddWithValue("@Sobrenome", objuser.Sobrenome);
cmd.Parameters.AddWithValue("@Nascimento", objuser.Nascimento);
cmd.Parameters.AddWithValue("@Query", 2);
con.Open();
result = cmd.ExecuteScalar().ToString();
return result;
}
catch
{
return result = "";
}
finally
{
con.Close();
}
}
public string DeletarDados(Usuario objuser)
{
SqlConnection con = new SqlConnection("LocalDB)\MSSQLLocalDB");
string result = "";
try
{
con = new SqlConnection(ConfigurationManager.ConnectionStrings["mycon"].ToString());
SqlCommand cmd = new SqlCommand("Usp_InserirAtualizarDeletar_Usuario", con)
{
CommandType = CommandType.StoredProcedure
};
cmd.Parameters.AddWithValue("@ID", objuser.ID);
cmd.Parameters.AddWithValue("@Nome", null);
cmd.Parameters.AddWithValue("@Sobrenome", null);
cmd.Parameters.AddWithValue("@Nascimento", null);
cmd.Parameters.AddWithValue("@Query", 3);
con.Open();
result = cmd.ExecuteScalar().ToString();
return result;
}
catch
{
return result = "";
}
finally
{
con.Close();
}
}
public List<Usuario> SelecionarTodosDados()
{
SqlConnection con = null;
DataSet ds = null;
List<Usuario> userlist = null;
try
{
con = new SqlConnection(ConfigurationManager.ConnectionStrings["mycon"].ToString());
SqlCommand cmd = new SqlCommand("Usp_InserirAtualizarDeletar_Usuario", con)
{
CommandType = CommandType.StoredProcedure
};
cmd.Parameters.AddWithValue("@ID", null);
cmd.Parameters.AddWithValue("@Nome", null);
cmd.Parameters.AddWithValue("@Sobrenome", null);
cmd.Parameters.AddWithValue("@Nascimento", null);
cmd.Parameters.AddWithValue("@Query", 4);
con.Open();
SqlDataAdapter da = new SqlDataAdapter
{
SelectCommand = cmd
};
ds = new DataSet();
da.Fill(ds);
userlist = new List<Usuario>();
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
Usuario cobj = new Usuario
{
ID = Convert.ToInt32(ds.Tables[0].Rows[i]["ID"].ToString()),
Nome = ds.Tables[0].Rows[i]["Nome"].ToString(),
Sobrenome = ds.Tables[0].Rows[i]["Sobrenome"].ToString(),
Nascimento = Convert.ToDateTime(ds.Tables[0].Rows[i]["Nascimento"].ToString())
};
userlist.Add(cobj);
}
return userlist;
}
catch
{
return userlist;
}
finally
{
con.Close();
}
}
public Usuario SelecionarDadosbyID(string ID)
{
SqlConnection con = null;
DataSet ds = null;
Usuario cobj = null;
try
{
con = new SqlConnection(ConfigurationManager.ConnectionStrings["mycon"].ToString());
SqlCommand cmd = new SqlCommand("Usp_InserirAtualizarDeletar_Usuario", con)
{
CommandType = CommandType.StoredProcedure
};
cmd.Parameters.AddWithValue("@ID", ID);
cmd.Parameters.AddWithValue("@Nome", null);
cmd.Parameters.AddWithValue("@Sobrenome", null);
cmd.Parameters.AddWithValue("@Nascimento", null);
cmd.Parameters.AddWithValue("@Query", 5);
SqlDataAdapter da = new SqlDataAdapter
{
SelectCommand = cmd
};
ds = new DataSet();
da.Fill(ds);
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
cobj = new Usuario
{
ID = Convert.ToInt32(ds.Tables[0].Rows[i]["ID"].ToString()),
Nome = ds.Tables[0].Rows[i]["Nome"].ToString(),
Sobrenome = ds.Tables[0].Rows[i]["Sobrenome"].ToString(),
Nascimento = Convert.ToDateTime(ds.Tables[0].Rows[i]["Nascimento"].ToString())
};
}
return cobj;
}
catch
{
return cobj;
}
finally
{
con.Close();
}
}
}
}