SQL: Sequence Number on a Select Query

If you need to put a sequence number on the records from your SELECT query, you can do the following technique.

select @n := 0;
select @n:=@n+1 as rec, contactname from contact;

The first statement initializes the variable "n". The second statement uses the variable on the first statement.

A sample output record from the select statement is as follows:

rec	contactname
1	Marilou
2	Ivan
3	Harris
4	Nelson
5	Peter