One thing I forgot: You will need to add the separator to your search value (In your case underscore):
searchValue = "123" + "_"; Otherwise you might get unwanted multiple results! /SJ On Mon, Aug 23, 2010 at 10:32 AM, Samuru Jackson < [email protected]> wrote: > Hi, > > I do it this way: > > The variable searchValue is my Prefix like in your case 123 would be: > > searchValue = "123"; > > PrefixFilter prefixFilter = new PrefixFilter(Bytes.toBytes(searchValue)); > Scan scan = new Scan(); > scan.addFamily(Bytes.toBytes(this.REF_FAM)); > scan.setFilter(prefixFilter); > ResultScanner resultScanner = hBaseTable.getScanner(scan); > > Now you can iterate over the resultScanner. > > Is this what you were looking for? > > /SJ > > > > > > On Mon, Aug 23, 2010 at 6:00 AM, Michelan Arendse <[email protected]> > wrote: > > Hi, > > > > Thanks for the responses but it's still not what I am really looking for. > > > > The row id looks something like: number_string so it would be 123_foo, > 123_foo2 123_foo3. > > So now I want to find all the foo's that are related to the first half of > the key which is "123". > > > > Also I can't add start row if I do not know where 123 starts. And I can't > search for the start row, as I need this to be very fast. > > > > Thanks. > > > > > > -----Original Message----- > > From: Ryan Rawson [mailto:[email protected]] > > Sent: 17 August 2010 09:01 PM > > To: [email protected] > > Subject: Re: Scanning half a key or value in HBase > > > > Hey, > > > > One thing to watch out for is ascii with separator variable length > > keys, you would think if your key structure was: > > > > foo:bar > > > > starting at 'foo' and ending at 'foo:' might give you only keys which > > start with 'foo:' but this doesn't work like that. You also get keys > > like: > > foo123:bar > > > > you must start the scan at 'foo:' but you can't just end it at 'foo;' > > (since next(:) == ';' in ascii), this has to do with the ordering of > > ASCII, for a reference look at http://www.asciitable.com/ > > > > The bug-free solution is to start your scan at 'foo:' and use a prefix > > filter set to 'foo:'. > > > > If you are scanning fixed-width keys, eg: binary conversions of longs, > > then the [start,start+1) solution works. > > > > On Tue, Aug 17, 2010 at 5:59 AM, Andrey Stepachev <[email protected]> > wrote: > >> Use scan where start key is <first_half_of_key> itself as bytearray, and > >> stop key is <first_half_of_key> with last byte in bytearray + 1. > >> > >> example > >> abc% should be scan(abc, abd) > >> > >> 2010/8/17 Michelan Arendse <[email protected]>: > >>> Hi > >>> > >>> I am not sure if this is possible in HBase. What I am trying to do is > scan on a HBase table with something similar to how SQL would do it. > >>> e.g. SELECT * > >>> FROM <table> > >>> WHERE <primary key> LIKE '<first_half_of_key>%' ; > >>> > >>> So as you can see from above I want to scan the table with only part of > the row key, since the key is a combination of 2 fields in the table. > >>> > >>> Regards, > >>> Michelan Arendse > >>> > >>> > >>> > >> > > > >
