CODEWITHSUNDEEP
javamysql
Scooter
Scooter

Reputation: 1079

Java MySQL Iterate Backwards through ResultSet

I've executed a query that returns a ResultSet of data that I would like to iterate backwards over. In a for loop it would look like this:

for (int i = MAX; i >=0; i--){
     // do something
}

The only problem is I don't have a a column in my DB that is perfectly sequential, instead I have an id that is unique, but sometimes skips numbers. So, using the actual result set, is there some way I can do while(set.next()) {...} but in reverse? Thanks.

Upvotes: 3

Views: 1808

Answers (1)

Shreyas Chavan
Shreyas Chavan

Reputation: 1099

You can traverse a resultset backwards if you have a scrollable resultset.You can get this by doing

ResultSet.TYPE_SCROLL_INSENSITIVE and ResultSet.CONCUR_READ_ONLYwhen creating the statement.

Then you can use resultset.last() to get to the last entry and traverse backwards using resultset.previous()

Edit: If you want results in descending order of the non-sequential ids that you mentioned, you can retrieve the resultset in descending order by doing order by id desc and then traverse the resultset normally

Upvotes: 6

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