Generating sequential number

Question

Hi,

I am writing a order manag sys , what is the best way to generate sequential order number somthing like ORD00001 , ORD00002 ....

Thanks

Answer 1

Please add this function to your project to get the autoIncrementOrderID.

public string AutoIncrementOrderID()
{
/*
	//wrt the code for retrieving the specific column value(OrderID)
	//by sorting the column dec ordr(eg: select top 1 o_id from orderTab order by o_id 	
	//desc.
*/
	string new_ord_id="";
	int ord_num=0;

	string ord_id=//here u have to get the value from the table.

	if(has rows)
	{
		ord_num=Int32.parse(ord_id.SubString(3,5));
	}

	ord_num++;

	if((ord_num>=1) && (order_num<=9))
	{
		
		new_ord_id="ORD0000"+ord_num;
	}
	else if ((ord_num>=10) && (order_num<=99))
	{
		
		new_ord_id="ORD000"+ord_num;
	}
	else if ((ord_num>=100) && (order_num<=999))
	{
		
		new_ord_id="ORD00"+ord_num;
	}
/*You can include as many as if conditions as per your requirment*/
	return new_ord_id;
	
}

Thanks and Regards.

K

Answer 2

thanks for your reply , the only proble with this approach is if two or more users try to create order at same time you might end up with duplicate order number.

Answer 3

Hi XFahadx

 its Better to use Database functionality for update of to avoid dupilcates

make a table according to your need and generate the number...accordingly

---

Harshad..... Always 4 U

Answer 4

If it is multi user environment then work with Transaction with isolation levels.

Answer 5

Virtually all databases have a mechanism for generating a unique incrementing ID.  Just use that.  Don't re-invent the wheel.  It will do it efficiently, and it will handle all of the corner cases of a highly multithreaded environment.

If you really, really need the ORD in front with leading zeros then just make a derived column that takes the auto-generated ID and appends the ORD+padded zeros.

Answer 6

Don't use all those if statements. Use actual string formatting.

new_ord_id = "ORD" + ord_num.ToString("D6");