How do I validate Inserting PK to database using linq to sql

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I have to insert values in a sql database using textbox. The ID field is the primary key. Now If the user inputs duplicate ID value there will be a messagebox displaying error alert and if the value is not duplicate then it will insert data to database. The problem is when the Id is already in database it is showing the error but when the new ID is entered the data is not stored to database. Kindly help!
The Code is as follows.....

C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace CustomerMaster
{
    public partial class CustomerMaster : System.Web.UI.Page
    {

        private void AddData()
        {
            
            OperationsDataContext AddDb = new OperationsDataContext();
            CustomerMast cm = new CustomerMast();
            
                        
            cm.CustomerCode = txtCustCde.Text;
            cm.CustomerName = txtCustName.Text;
            cm.CustomerAddress = txtCustAdd.Text;
            cm.BrkrCode = txtBrkCode.Text;
            cm.BrokerName = txtBrkName.Text.
            cm.CrrCode = txtCrrCode.CarrierCode;
            cm.CarrierName =  txtCrrName.Text;
	cm.StnCode=sm.StationCode;
            cm.StationName = txtStnName.Text;
            cm.VatNo=txtVatNo.Text;
            cm.TinNo=txtTinNo.Text;
            cm.TMCO=txtTMCONo.Text;
            cm.PanNo = txtPAN.Text;

var chk = from c in AddDb.CustomerMasts where c.CustomerCode == txtCustCde.Text select c;
            foreach (CustomerMast c in chk)
            {
                if (c.CustomerCode == txtCustCde.Text)
                {
                    Response.Write("Error! CustomerCode Exits");

                }
                else if(c.CustomerCode != txtCustCde.Text)
                {
                    AddDb.BrokerMasts.InsertOnSubmit(bm);
                    AddDb.CarrierMasts.InsertOnSubmit(crm);
                    AddDb.StationMasts.InsertOnSubmit(sm);
                    AddDb.CustomerMasts.InsertOnSubmit(cm);

                    AddDb.SubmitChanges();
                    
                }
            }
           
        }

        protected void btnAdd_Click(object sender, EventArgs e)
        {
          AddData();
            
    }
    }
}

Posted 4-Jun-15 19:56pm

Member 11341510

Updated 4-Jun-15 20:10pm

DamithSL

v2

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Comments

Sinisa Hajnal 5-Jun-15 2:14am

Not enough data. Post InsertOnSubmit code. Before that check the following:
- values of bm, crm and sm (they are used, but not shown in the example above)
- values of cm
- connection string / database context - is everything OK
- put TRY..CATCH block around submits, see if you get the error
- on the page add a label into which you will write the message, don't write directly on the page. Alternatively, create javascript function that calls alert dialog with the message and call that.

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Staffan Bruun · Accepted Answer · 2015-06-04T20:34:00

Your test is redundant, since you are already querying only for matching records. In this case, you will get no rows if there is no match, therefore you will never hit the else clause in the loop.

Instead, it is enough to check if there are any matching records at all. The example below shows how (note that you can put a condition straight into Any() instead of specifying Where()).

C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
 
namespace CustomerMaster
{
    public partial class CustomerMaster : System.Web.UI.Page
    {
 
        private void AddData()
        {
            
            OperationsDataContext AddDb = new OperationsDataContext();
            CustomerMast cm = new CustomerMast();
            
                        
            cm.CustomerCode = txtCustCde.Text;
            cm.CustomerName = txtCustName.Text;
            cm.CustomerAddress = txtCustAdd.Text;
            cm.BrkrCode = txtBrkCode.Text;
            cm.BrokerName = txtBrkName.Text.
            cm.CrrCode = txtCrrCode.CarrierCode;
            cm.CarrierName =  txtCrrName.Text;
            cm.StnCode=sm.StationCode;
            cm.StationName = txtStnName.Text;
            cm.VatNo=txtVatNo.Text;
            cm.TinNo=txtTinNo.Text;
            cm.TMCO=txtTMCONo.Text;
            cm.PanNo = txtPAN.Text;
			
	    if(AddDb.CustomerMasts.Any(c=>c.CustomerCode == txtCustCde.Text))
            {
	        Response.Write("Error! CustomerCode Exits");
	    }
	    else
	    {
                AddDb.BrokerMasts.InsertOnSubmit(bm);
                AddDb.CarrierMasts.InsertOnSubmit(crm);
                AddDb.StationMasts.InsertOnSubmit(sm);
                AddDb.CustomerMasts.InsertOnSubmit(cm);

	        AddDb.SubmitChanges();
            }         
        }
 
        protected void btnAdd_Click(object sender, EventArgs e)
        {
            AddData();
        }
    }
}