Find a missing number ?

We have a database table, with a field ( int (4) ) , we'll call it
transid.
The field is being populated by an unknown random formula in a third party
program.
I have another program that i am writing that needs to insert records into
this table.
This field, transid must be unique.
I started in MY program with a function that said "select max(transid) from
table" , newid=max(transid) + 1, insert into table (newid,blah blah blah)
Problem being that because the OTHER program is using random numbers, it
eventually put in a value that is the max length of an int(4) field.
SO - i changed my syntax to be newid=(select max(transid) from table where
transid<1000000)+1 - works fine for a while until the other program came
along and inserted a value of 9999996 - so then, only my next four
transactions worked until i hit 9999999 and then the number kept repeating,
no longer unique, insert fails.
SO my question - is there a sql function that would say:
"Find me a number that is not already used in the field transid in table" '
Im trying to figure with EXISTS, NOT EXISTS, etc, but i cant make anything
work.
Appreciate any assistance !
Thanks,
M.Coz wrote:
> SO my question - is there a sql function that would say:
> "Find me a number that is not already used in the field transid in
> table" ' Im trying to figure with EXISTS, NOT EXISTS, etc, but i
> cant make anything work.
See this thread
SQL Problem: How to find UNUSED numbers
http://groups.google.pl/groups?hl=pl&lr=&ie=UTF-8&oe=UTF-8&th=a3eb815a529ae1c5&rnum=1
sincerely,
--
Sebastian K. Zaklada
Skilled Software
http://www.skilledsoftware.com
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