ispiro ispiro - 7 months ago 10
SQL Question

How do I create a serial number in SQL for INSERT?

I'm saving data to a table, but I also need a column with a serial number. How do I do that? (I'm doing this in C#, perhaps it matters.)

This must be pretty simple, but googling hasn't been successful.

EDIT: I don't want to just save an integer. I want to give SQL a command to create it when saving, because if I create an integer and save it between creating it and saving it – another query might try to save the same number at the same time, and I'll get two entries with the same number.)

Answer

Use IDENTITY:

CREATE TABLE YourTable
(
    ID         INT IDENTITY
)

Each time you insert a new record SQL Server will take care of incrementing this value for you (no two records will have the same number, it is unique).

http://msdn.microsoft.com/en-us/library/aa933196(v=sql.80).aspx