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sunflower
Asked: 2020-03-09 11:06:12 +0800 CST 2020-03-09 11:06:12 +0800 CST

PROBLEM WITH SQL QUERY IN C# ASP .NET

  • 772

I have a webform project in asp .net with c# and in my sql query I need data that the user is going to provide.

The week field is entered in a textbox in webform1 and I have the query in webform2. According to that data, it will show me certain records in a gridview. In addition to the login cod_user. Next I show the code

Mistakes:

*'Value cannot be null. Parameter name: String' of the line: int value = Int32.Parse(Request.QueryString["week"]);

*'The query with parameters '(@cod varchar(5))SELECT blah blah' expects the parameter '@cod', which was not supplied.'

ORIGIN PAGE

   protected void BUTTON1_Click(object sender, EventArgs e)
   {
       string semana = sem.Text;
       if (sem.Text != null)
       {
         Response.Redirect("webform2.aspx?semana=" + semana);
       }
       else {
           Response.Redirect("webform1.aspx");
       }
   }

DESTINATION PAGE

protectedvoid Page_Load(object sender, EventArgs e)
    {
        int valor = Int32.Parse(Request.QueryString["semana"]);// valor que viene de otro webform
       SqlConnection con = newSqlConnection(ConfigurationManager.ConnectionStrings["cn"].ToString());

        con.Open();
            SqlCommand cmd = newSqlCommand("SELECT WHERE(Sem.Semana = '@sem') AND(Cab.Cod_user= '@cod') AND(etc...", con);
         cmd.Parameters.Add("@sem", SqlDbType.TinyInt, 3);
        cmd.Parameters["@sem"].Value = valor;
       cmd.Parameters.Add("@cod", SqlDbType.VarChar, 5);

cmd.Parameters["@cod"].Value = Session["Cod_user"]; 

SqlDataAdapter da = newSqlDataAdapter(cmd);
            DataTable dt = newDataTable();
            da.Fill(dt);
           gridview1.Visible = true;
           gridview1.DataSource = dt;
           gridview.DataBind();
         con.Close();
        }

I hope you can help me

Cheers

Thank you

c#

1 Answers

  1. Best Answer

    Let's go by parts, verify that you have data with the following lines of code

    var requestSemana = Request.QueryString["semana"];
var laSessionActual = Session["Cod_user"]; 
int valor = Int32.Parse(Request.QueryString["semana"]); //Aquí coloca un breakpoint.
//De esta manera podrás ver la información de las 2 variables anteriores.

    Update

    For the Cod_User, replace:

    cmd.Parameters["@cod"].Value = Session["Cod_user"];

    By:

    cmd.Parameters["@cod"].Value = (string)Session["Cod_user"];

    For the week:

    Replaces:

    int valor = Int32.Parse(Request.QueryString["semana"]);

    By:

    int valor = Convert.ToInt32(Request.QueryString["semana"]);
    • 1