Visual studio 2010 C# SQLCommand.ExecuteNonQuery SQLException Error converting data type varchar to int

Question

i tried inserting data in my database but my SQLCommand.ExecuteNonQuery throws an SQLException Error "converting data type varchar to int."

this is my aspx.cs

    public void FillDropdownList()
    {
        if (!IsPostBack)
        {
            String[] Semesters = { "DIS R", "DIS M", "DDOA", "DECO R", "DECO L", "CRIA" };
            for (int i = 0; i < Semesters.Length; i++)
            {
                ddSemester.Items.Add(Semesters[i].ToString());
            }
            String[] Periodes = { "2013 P2", "2014 P1", "2014 P2" };
            for (int i = 0; i < Periodes.Length; i++)
            {
                ddPeriode.Items.Add(Periodes[i].ToString());
            }

        }
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        string Connectionstring = @"Data Source=mossserver1;Initial Catalog=Sharepoint;Integrated Security=SSPI;";
        SqlConnection Datacon = new SqlConnection(Connectionstring);
        SqlCommand Datacommand = new SqlCommand("sprocSemesterkeuze");
        Datacommand.CommandType = CommandType.StoredProcedure;
        Datacommand.Connection = Datacon;

        //de komende statements herhalen tot je alle parameters hebt ingevoerd
        string leerlingnaam = getStringAfterSlash(SPContext.Current.Site.RootWeb.CurrentUser.Name);
        SqlParameter llnaam = new SqlParameter();
        llnaam.ParameterName = "@leerlingnaam"; //bv @artikelnr, maar dat ligt aan wat je in de stored procedure hebt
        llnaam.SqlDbType = SqlDbType.VarChar;  //kan ook een int zijn of whatever je in de database hebt gedefinieerd
        llnaam.Value = (string)leerlingnaam;
        llnaam.Direction = ParameterDirection.Input;
        Datacommand.Parameters.Add(llnaam);

        SqlParameter semesterkeuze = new SqlParameter();
        semesterkeuze.ParameterName = "@semesterkeuze"; //bv @artikelnr, maar dat ligt aan wat je in de stored procedure hebt
        semesterkeuze.SqlDbType = SqlDbType.VarChar;  //kan ook een int zijn of whatever je in de database hebt gedefinieerd
        semesterkeuze.Value = (string)ddSemester.Text;
        semesterkeuze.Direction = ParameterDirection.Input;
        Datacommand.Parameters.Add(semesterkeuze);

        SqlParameter slber = new SqlParameter();
        slber.ParameterName = "@slber"; //bv @artikelnr, maar dat ligt aan wat je in de stored procedure hebt
        slber.SqlDbType = SqlDbType.VarChar;  //kan ook een int zijn of whatever je in de database hebt gedefinieerd
        slber.Value = (string)tbSlber.Text;
        slber.Direction = ParameterDirection.Input;
        Datacommand.Parameters.Add(slber);

        SqlParameter periode = new SqlParameter();
        periode.ParameterName = "@periode"; //bv @artikelnr, maar dat ligt aan wat je in de stored procedure hebt
        periode.SqlDbType = SqlDbType.VarChar;  //kan ook een int zijn of whatever je in de database hebt gedefinieerd
        periode.Value = (string)ddPeriode.Text;
        periode.Direction = ParameterDirection.Input;
        Datacommand.Parameters.Add(periode);

        Datacon.Open();

        Datacommand.ExecuteNonQuery();
        Datacommand.Dispose();
        Datacon.Dispose();



    }

    protected string getStringAfterSlash(string input)
    {
        ArrayList matches = new ArrayList();
        foreach (Match match in Regex.Matches(input, "\\\\"))
        {
            matches.Add(match.Index);
        }
        if (matches.Count > 0)
        {
            return input.Substring((int)matches[matches.Count - 1] + 1);
        }
        return input;
    }

}

}

and this is my aspx file

<%@ Assembly Name="$SharePoint.Project.AssemblyFullName$" %>
<%@ Assembly Name="Microsoft.Web.CommandUI, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> 
<%@ Register Tagprefix="SharePoint" Namespace="Microsoft.SharePoint.WebControls" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> 
<%@ Register Tagprefix="Utilities" Namespace="Microsoft.SharePoint.Utilities" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register Tagprefix="asp" Namespace="System.Web.UI" Assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>
<%@ Import Namespace="Microsoft.SharePoint" %> 
<%@ Register Tagprefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="StudentSemesterKeuzeUserControl.ascx.cs" Inherits="StudentSemesterkeuze.StudentSemesterKeuze.StudentSemesterKeuzeUserControl" %>
<asp:Label ID="lblSemester" runat="server" Text="Kies Semester"  Width = " 100px"></asp:Label>
<asp:DropDownList ID="ddSemester" runat="server">
</asp:DropDownList>
<br />
<asp:Label ID="lblPeriode" runat="server" Text="Kies Periode" Width = " 100px"></asp:Label>
<asp:DropDownList ID="ddPeriode" runat="server">
</asp:DropDownList>
<br />
<asp:Label ID="Label1" runat="server" Text="SLB'er Code"></asp:Label>
<asp:TextBox ID="tbSlber" runat="server"></asp:TextBox>
<br />
<asp:Button ID="Button1" runat="server" Text="Stuur semesterkeuze" 
    onclick="Button1_Click" />

and last but not least, my stored procedure

create procedure sprocSemesterkeuze
@leerlingnaam VARCHAR(255),
@semesterkeuze VARCHAR(255),
@slber          VARCHAR(255),
@periode        VARCHAR(255)
as
begin

Insert into Semesterkeuze(leerlingnummer,semesterkeuze,[status],slber,datum,opmerkingen,periode)
values((select leerlingnummer from ToetsCijfers where leerlingnaam = @leerlingnaam),@semesterkeuze, 'Pending',@slber,CURRENT_TIMESTAMP,null,@periode)


end

i get the exception at Datacommand.ExecuteNonQuery(); in my aspx.cs file. Can someone please help?

this is how my table looks like puu.sh/54Ca5.png

Answer 1

i found the solution. in my selectstatement (select leerlingnummer from ToetsCijfers where leerlingnaam = @leerlingnaam) i added a group by clause (group by leerlingnummer) and it worked.

but i am not sure why. can anyone tell me that?

Answer 2

The error seems simple. You do have an INT column in your Semesterkeuze database, for which you are trying to get the value to insert into with the following select statement:

(select leerlingnummer from ToetsCijfers where leerlingnaam = @leerlingnaam)

check the table definition of ToetsCijfers and it seems like leerlingnummer is not an INT there, but a varchar.