Ik kan niet echt bevatten waarom je dit zou willen, maar de truc zit um in het gebruik van de ingebouwde substring functie van mysql.
Input
CREATE TABLE `test` (
`id` int(10) unsigned NOT NULL auto_increment,
`field1` varchar(255) default NULL,
`field2` varchar(255) default NULL,
PRIMARY KEY (`id`)
)
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '10', 'Lorem Ipsum 10');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '11', 'Lorem Ipsum 11');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '12', 'Lorem Ipsum 12');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '13', 'Lorem Ipsum 13');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '14', 'Lorem Ipsum 14');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '15', 'Lorem Ipsum 15');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '16', 'Lorem Ipsum 16');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '17', 'Lorem Ipsum 17');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '18', 'Lorem Ipsum 18');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '19', 'Lorem Ipsum 19');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '20', 'Lorem Ipsum 20');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '21', 'Lorem Ipsum 21');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '22', 'Lorem Ipsum 22');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '23', 'Lorem Ipsum 23');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '24', 'Lorem Ipsum 24');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '25', 'Lorem Ipsum 25');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '26', 'Lorem Ipsum 26');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '27', 'Lorem Ipsum 27');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '28', 'Lorem Ipsum 28');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '29', 'Lorem Ipsum 29');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '30', 'Lorem Ipsum 30');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '31', 'Lorem Ipsum 31');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '32', 'Lorem Ipsum 32');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '33', 'Lorem Ipsum 33');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '34', 'Lorem Ipsum 34');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '35', 'Lorem Ipsum 35');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '36', 'Lorem Ipsum 36');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '37', 'Lorem Ipsum 37');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '38', 'Lorem Ipsum 38');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '39', 'Lorem Ipsum 39');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '40', 'Lorem Ipsum 40');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '41', 'Lorem Ipsum 41');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '42', 'Lorem Ipsum 42');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '43', 'Lorem Ipsum 43');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '44', 'Lorem Ipsum 44');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '45', 'Lorem Ipsum 45');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '46', 'Lorem Ipsum 46');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '47', 'Lorem Ipsum 47');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '48', 'Lorem Ipsum 48');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '49', 'Lorem Ipsum 49');
INSERT INTO `test` (`id` , `field1` , `field2`) VALUES ('', '50', 'Lorem Ipsum 50');
SQL:
SELECT DISTINCT substring(`field1`, 2, 1) AS `_char`, id, field1, field2
FROM `test`
GROUP BY `_char`
Resultaat:
0 2 10 Lorem Ipsum 10
1 3 11 Lorem Ipsum 11
2 4 12 Lorem Ipsum 12
3 5 13 Lorem Ipsum 13
4 6 14 Lorem Ipsum 14
5 7 15 Lorem Ipsum 15
6 8 16 Lorem Ipsum 16
7 9 17 Lorem Ipsum 17
8 10 18 Lorem Ipsum 18
9 11 19 Lorem Ipsum 19