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im using windows application in c#. i want to generate a ID no in a text box when i run the form first time. while second time, the number generated must be +1 of the old number. can be given condition like between 10000 and 20000.for eg: 00154 for first time means next time when i run the form i want 00155.
[no name] 5-Sep-12 12:23pm
Okay so go ahead and do that.
sahabiswarup 6-Sep-12 2:26am
select max(cust_id)+1 as CustID from customer_master where cust_id like '10000%'

The first question would be WHY?

If you're going to use this as a primary key in a table, DON'T!
Here is an example to generate random number as well as string..

Hope it helps you to understand the logic..and you can create whatever condition you want.

StringBuilder builder = new StringBuilder();
        builder.Append(RandomString(4, true));
        builder.Append(RandomNumber(1000, 9999));

Generate random number
private string RandomString(int size, bool lowerCase)
        StringBuilder builder = new StringBuilder();
        Random random = new Random();
        char ch;
        for (int i = 0; i < size; i++)
            ch = Convert.ToChar(Convert.ToInt32(Math.Floor(26 * random.NextDouble() + 65)));
        if (lowerCase)
            return builder.ToString().ToLower();
        return builder.ToString();

Generate Random Number
private int RandomNumber(int min, int max)
    Random random = new Random();
    return random.Next(min, max);

You may also apply query to generate serial number
string sqlQuery = "select max(" + colName + ") + 1 from " + tblName;

If you still have any query don't hesitate to ask..
Happy coding.
Dave Kreskowiak 5-Sep-12 13:44pm
string sqlQuery = "select max(" + colName + ") + 1 from " + tblName;

And what would happen if two clients executed this code at the same time??
sahabiswarup 6-Sep-12 2:28am
that query doesn't executed at the same time; there must be some time difference between two request so i don't think that may be some problem.

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