Amir Michail wrote:
Hi,
I would like to copy rows from one table to another while copying
only the first row from sets of similar rows.
In particular, for rows in which two particular fields are the same, I would
like to copy only the first row in that set. The rows have more than these
two fields.
I know how to copy rows from one table to another, but how do I suppress
similar rows in this way?
Amir
Hi Amir,
One way to solve this problem would be to put a filtering function in
the WHERE clause of the driving SELECT statement. Something like this:
INSERT INTO targetTable
SELECT * FROM sourceTable
WHERE isFirstInstance( tastyColumn1, tastyColumn2 ) = 1
Here isFirstInstance is a function which returns 1 the first time it
sees a given key combination and returns 0 on all subsequent sightings.
You, of course, have to write this user function.
Hope this helps,
-Rick
