Re: [GENERAL] Comparing bit in an integer field
On Mon, Nov 16, 2009 at 7:53 PM, A. Kretschmer < andreas.kretsch...@schollglas.com> wrote: > In response to Amitabh Kant : > > test=# select * from t1; > a1 > > 0 > 12 > 8 > 0 > 1 > 10 > 7 > 19 > (8 rows) > > test=*# select a1 from t1 where (a1>>2)::bit = B'1'; > a1 > > 12 > 7 > (2 rows) > > > Regards, Andreas > Thanks. That should solve my problem. Amitabh
Re: [GENERAL] Comparing bit in an integer field
2009/11/16 A. Kretschmer : > In response to Amitabh Kant : >> Hello >> >> I need to compare the bit values of a integer field in my table. For >> example, I >> have a table called "t1" with just one field "a1" having following values: >> >> a1 >> == >> 0 >> 12 >> 8 >> 0 >> 1 >> 10 >> 7 >> 19 >> >> I am trying to fetch all records where the 3rd binary bit is 1, which from >> the >> above example should be 12 (1100) and 7 (0111). If I convert the >> values >> to binary and store it as string, I can easily compare them using substr, but >> would rather like to retain the integer field. I have tried using the get_bit >> function, but it seems my understanding of the function is not correct. > > test=# select * from t1; > a1 > > 0 > 12 > 8 > 0 > 1 > 10 > 7 > 19 > (8 rows) > > test=*# select a1 from t1 where (a1>>2)::bit = B'1'; > a1 > > 12 > 7 > (2 rows) > Ah, bit-shifting. Told you there'd be a cleaner way ;) -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Comparing bit in an integer field
In response to Amitabh Kant : > Hello > > I need to compare the bit values of a integer field in my table. For > example, I > have a table called "t1" with just one field "a1" having following values: > > a1 > == > 0 > 12 > 8 > 0 > 1 > 10 > 7 > 19 > > I am trying to fetch all records where the 3rd binary bit is 1, which from the > above example should be 12 (1100) and 7 (0111). If I convert the > values > to binary and store it as string, I can easily compare them using substr, but > would rather like to retain the integer field. I have tried using the get_bit > function, but it seems my understanding of the function is not correct. test=# select * from t1; a1 0 12 8 0 1 10 7 19 (8 rows) test=*# select a1 from t1 where (a1>>2)::bit = B'1'; a1 12 7 (2 rows) Regards, Andreas -- Andreas Kretschmer Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header) GnuPG: 0x31720C99, 1006 CCB4 A326 1D42 6431 2EB0 389D 1DC2 3172 0C99 -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Comparing bit in an integer field
2009/11/16 Amitabh Kant : > Hello > > I need to compare the bit values of a integer field in my table. For > example, I have a table called "t1" with just one field "a1" having > following values: > > a1 > == > 0 > 12 > 8 > 0 > 1 > 10 > 7 > 19 > > I am trying to fetch all records where the 3rd binary bit is 1, which from > the above example should be 12 (1100) and 7 (0111). If I convert the > values to binary and store it as string, I can easily compare them using > substr, but would rather like to retain the integer field. I have tried > using the get_bit function, but it seems my understanding of the function is > not correct. > > I would appreciate any help in this regard. > > > Amitabh > There's probably a clean way of doing this, but you could do: SELECT a1 FROM t1 WHERE (a1::bit(10) & 4::bit(10))::int = 4; a1 12 7 (2 rows) Regards Thom -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
