asp.net - c#.net Error: There is already an open DataReader associated with this Command which must be closed first -

help, new asp.net c#. tried codes once before didn't seems have error. can't seems figure make changes to.

sever error : there open datareader associated command must closed first.

codes:

string strconnectionstring = configurationmanager.connectionstrings["fypdb"].connectionstring;  sqlconnection myconnect = new sqlconnection(strconnectionstring);  string strcommandtext = "select promoid fypdb.dbo.promotions membershiptype '%' + @membership + '%' , defaults '%' + @defaults + '%'";  try {     string ddlmembership = ((dropdownlist)dvinsertpromotion.findcontrol("ddladdmembershiplist")).selecteditem.tostring();     string ddldefault = ((radiobuttonlist)dvinsertpromotion.findcontrol("radiobuttonlist2")).text.tostring();      dataset da = dal.retrievemembership(ddlmembership, ddldefault);     sitegridview.datasource = da;     sitegridview.databind();       sqlcommand cmd = new sqlcommand(strcommandtext, myconnect);      cmd.parameters.add("@membership", sqldbtype.nvarchar);     cmd.parameters.add("@defaults", sqldbtype.nvarchar);      cmd.parameters["@membership"].value = ddlmembership;     cmd.parameters["@defaults"].value = ddldefault;      myconnect.open();     sqldatareader reader = cmd.executereader();       if (reader.read())     {         //get number of count         //int count = da.tables[0].rows.count;         int count = (int)cmd.executescalar();          if (count == 1)         {             defaultcomfirm.show();             promotion = false;         }      }     else     {         label6.text = "error didnt go through";         label6.forecolor = system.drawing.color.gray;         label6.visible = true;     }     reader.close(); }   {     myconnect.close(); } 

you using same command object 2 times:

1. sqldatareader reader = cmd.executereader();
2. int count = (int)cmd.executescalar();

this not possible.

it not necessary use reader if want have count of rows. in case can use executescalar.

like this:

string strcommandtext = "select count(promoid) fypdb.dbo.promotions membershiptype '%' + @membership + '%' , defaults '%' + @defaults + '%'";         try         {         ...         int count = (int)cmd.executescalar();         ... 

regards oliver