Vivek Khera wrote:
> On Dec 7, 2007, at 11:42 AM, Colin Wetherbee wrote:
>
>> You can do this with a conditional. Something like the following
>> should work.
>>
>> IF
>> NOT (a query matching your data returns rows)
>> THEN
>> INSERT (your new data)
>
> There exists a race condition here unless you've locked your tables.
Yes, clearly. In the context of the thread, I was assuming my algorithm
would be implemented as an atomic transaction.
For what it's worth, the real algorithm would be as follows. I hadn't
had enough coffee yet, and I forgot the UPDATE bit.
IF
(a query matching your old data returns rows)
THEN
UPDATE with your new data
ELSE
INSERT your new data
Colin