Hi! I have a "SQL query construction" question that I hope someone can help me with. After comparing a bunch of DNA fragments (see name below) with a larger reference sequence I get a ordered list ranked according to similarities, and with start/stop co-ordinates where the fragments map to the reference sequence:
+------+------+-------+------+----------+ | name | rank | start | stop | sub_rank | +------+------+-------+------+----------+ | A | 1 | 1 | 1000 | NULL | | B | 2 | 2 | 998 | NULL | | C | 4 | 1100 | 2000 | NULL | | D | 3 | 3050 | 4100 | NULL | | E | 5 | 2040 | 3000 | NULL | | F | 6 | 1102 | 2000 | NULL | | G | 7 | 1098 | 1998 | NULL | | H | 8 | 3048 | 4100 | NULL | | I | 9 | 3051 | 4102 | NULL | +------+------+-------+------+----------+ A graphical representation of fragments mapped to the ref sequence: ref========================================> 1 A------> 2 B----> 3 D------> 4 C------> 5 E----> 6 F-------> 7 G-------> 8 H-------> 9 I-------> Now, I want to group fragments in each overlapping position and sub-rank them according to their rank in that position. The final table would then look like: +------+------+-------+------+----------+ | name | rank | start | stop | sub_rank | +------+------+-------+------+----------+ | A | 1 | 1 | 1000 | 1 | | B | 2 | 2 | 998 | 2 | | C | 4 | 1100 | 2000 | 1 | | D | 3 | 3050 | 4100 | 1 | | E | 5 | 2040 | 3000 | 1 | | F | 6 | 1102 | 2000 | 2 | | G | 7 | 1098 | 1998 | 3 | | H | 8 | 3048 | 4100 | 2 | | I | 9 | 3051 | 4102 | 3 | +------+------+-------+------+----------+ Is this possible to achieve using SQL queries alone (perhaps with GROUP BY, nested SELECTs etc)? I've managed to do this with a Perl-DBI script, but would much prefer to do it completely with MySQL instead. The Perl code is below and below that is the MySQL-dump of the test data set... Many thanks in advance! Marcus while (@{$dbh->selectcol_arrayref("SELECT rank FROM test WHERE sub_rank IS NULL")}) { @null_sub_ranks = @{$dbh->selectcol_arrayref("SELECT rank FROM test WHERE sub_rank IS NULL AND NOT (start>=(SELECT stop FROM test WHERE rank = (SELECT min(rank) FROM test WHERE sub_rank IS NULL)) OR stop <= (SELECT start FROM test WHERE rank = (SELECT min(rank) FROM test WHERE sub_rank IS NULL)))")}; for ($rank=0; $rank < scalar(@null_sub_ranks); $rank++ ) { $sub_rank = $rank + 1; $dbh->do("UPDATE test SET sub_rank=$sub_rank WHERE rank= $null_sub_ranks[$rank]"); } } -- MySQL dump 10.10 -- -- Host: localhost Database: bxb -- ------------------------------------------------------ -- Server version 5.0.22 /*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */; /*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */; /*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */; /*!40101 SET NAMES utf8 */; /*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */; /*!40103 SET TIME_ZONE='+00:00' */; /*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */; /*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */; /*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */; /*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */; -- -- Table structure for table `test` -- DROP TABLE IF EXISTS `test`; CREATE TABLE `test` ( `name` text, `rank` int(11) default NULL, `start` int(11) default NULL, `stop` int(11) default NULL, `sub_rank` int(11) default NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1; -- -- Dumping data for table `test` -- /*!40000 ALTER TABLE `test` DISABLE KEYS */; LOCK TABLES `test` WRITE; INSERT INTO `test` VALUES ('A',1,1,1000,NULL),('B',2,2,998,NULL),('C',4,1100,2000,NULL),('D',3,3050,4100,NULL),('E',5,2040,3000,NULL),('F',6,1102,2000,NULL),('G',7,1098,1998,NULL),('H',8,3048,4100,NULL),('I',9,3051,4102,NULL); UNLOCK TABLES; /*!40000 ALTER TABLE `test` ENABLE KEYS */; /*!40103 SET [EMAIL PROTECTED] */; /*!40101 SET [EMAIL PROTECTED] */; /*!40014 SET [EMAIL PROTECTED] */; /*!40014 SET [EMAIL PROTECTED] */; /*!40101 SET [EMAIL PROTECTED] */; /*!40101 SET [EMAIL PROTECTED] */; /*!40101 SET [EMAIL PROTECTED] */; /*!40111 SET [EMAIL PROTECTED] */; -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]