Is there any way to find the number or rows in a resultset without looping through it? and if that is the only way is there a way to get back to the start? If I am creating an array of Strings based on the number of returned rows, I need to know how big to make the array, but if I have to llop through it then I am at the end of the rs... Or should I use something other than a resultset to get my data? Thanks
a third alternative (and possibly not the best, but you'd have to check) is to perform the query twice, the first time as a count(*) operation. I agree that using a List implementation then converting to an Array (if required) may be your best bet.
Using 'select count (*)' is a good solution if the number of results is too big to put it into an array/ list/ whatever. The drawback is, that you could get a result, which is out of date, when you send the second query. To display a progressbar, it should be sufficient.
I wouldn't use the select count (*) option in this case because Joe was planning on storing all the data anyway (in his array.) It would add a server roundtrip. By storing/converting the results, it is only an optimized java operation.
... rs.last(); // set the resultset to the last row int lastRow = rs.getRow(); // get row count of last row rs.first() // go back to the first row for proecessing ...
Won't lastRow (or lastRow - 1) above, give you the number of rows? Again, as a previous poster said, this maybe only possible in JDBC3.0, and could throw an exception if rs.last() fails (because your result could be empty). You'll need to pretty it up a little with a try-catch block to pass muster.
Also, there are performance considerations, it will take time to run thru the entire resultset for the rs.last() to work, depending on how the resultset is buffered, but then again, looping thru all rows will take time too!