我遇到一个奇怪的问题,当我尝试使用LIMIT 40 OFFSET 40
获取一组结果的第二页时,整个查询的顺序不同,这意味着第一页中的某些行会再次出现,有些行从不显示。
我已经使用我的架构和数据的副本创建了一个SQL Fiddle,但是在这里非常有效:http://www.sqlfiddle.com/#!9/5d8d3e/1(底部也包含完整的示例)
在此示例中,第一个查询返回第一页,第二个查询返回第二页,并且第二页上的任何项目以前都没有出现在第一页中。正是您所期望的。
但是,当我在本地环境(装有Ubuntu和MySQL的Vagrant VM)和生产环境(Azure MySQL实例)上运行相同的操作时,都会得到奇怪的结果。
也就是说,无论第一页上的最后一项还是第二页的结果中都不会显示任何项。
不一定是“最后一项”有所不同的情况,我只是专门做了这样,所以只有一行带有“ owner_type_id” = 1的行才会显得比较容易。问题是,如果使用偏移量,排序似乎完全不同,这对我来说绝对没有意义。
我提供了我所看到的屏幕截图:
SELECT id, fm_id, name, owner_type FROM `stadiums_test` WHERE `capacity` > '70000' ORDER BY `owner_type` DESC LIMIT 40 OFFSET 0;
SELECT id, fm_id, name, owner_type FROM `stadiums_test` WHERE `capacity` > '70000' ORDER BY `owner_type` DESC LIMIT 40 OFFSET 0;
基本上,当使用LIMIT 40 OFFSET 0
时,体育场“ SantiagoBernabéu”是唯一显示“ owner_type”为“ 1”的体育场。
但是使用LIMIT 40 OFFSET 40
获取下一个“页面”时。仍然显示圣地亚哥·伯纳乌(SantiagoBernabéu),而从未显示“老特拉福德”体育场。
在此屏幕快照中,您可以看到没有limit
或offset
的完整结果:
值得注意的是,选择所有结果和限制结果时,“ owner_type”为“ 1”的项目的顺序也不同。
SELECT id, fm_id, name, owner_type FROM `stadiums_test` WHERE `capacity` > '70000' ORDER BY `owner_type` DESC;
我意识到我可以通过name
或id
进行类似二级排序的操作来解决此问题。但是我更想了解为什么会这样,而不仅仅是快速解决问题。
CREATE TABLE `stadiums_test` (
`id` int(10) unsigned NOT NULL,
`fm_id` bigint(20) unsigned DEFAULT NULL,
`name` varchar(100) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`owner_type` tinyint(3) unsigned DEFAULT NULL,
`capacity` mediumint(8) unsigned DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `fm_id` (`fm_id`)
) ENGINE=InnoDB CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
INSERT INTO `stadiums_test` (`id`, `fm_id`, `NAME`, `owner_type`, `capacity`)
VALUES
(6, 603, 'sfsfsfs', 1, 427773),
(74, 680, 'Old Trafford', 1, 75635),
(380, 1404, 'EverBank Field', 2, 76867),
(459, 1040, 'Camp Nou', 1, 99354),
(475, 1056, 'Santiago Bernabéu', 1, 81044),
(609, 1205, 'Giuseppe Meazza', NULL, 80018),
(632, 1229, 'San Paolo', NULL, 76824),
(688, 1293, 'SIGNAL IDUNA PARK', 1, 81365),
(707, 1317, 'Olympiastadion Berlin', 2, 74649),
(744, 1357, 'Ohio Stadium', NULL, 102329),
(746, 1359, 'The Cotton Bowl', 2, 92100),
(747, 1360, 'Arrowhead Stadium', 2, 76416),
(748, 1361, 'Rose Bowl', 2, 92542),
(1105, 102531, 'Mineirão', 2, 75783),
(1121, 102549, 'Morumbi', 1, 77011),
(1132, 102569, 'Yokohama International Stadium', 2, 72327),
(1186, 102969, 'Wembley', NULL, 90000),
(1228, 102984, 'Millennium Stadium', NULL, 74500),
(1229, 102987, 'Maracanã', 2, 78838),
(1249, 103037, 'Cairo International Stadium', NULL, 74100),
(1268, 103089, 'Surulere', NULL, 80000),
(1280, 103142, 'Olympic Stadium', 2, 72000),
(1281, 103143, 'Estadio Azteca', 1, 81070),
(1317, 103241, 'Gelora Bung Karno', 2, 77193),
(1318, 103242, 'Azadi', 2, 84412),
(1324, 103248, 'May Day Stadium', 2, 114000),
(1329, 103255, 'Shah Alam', 2, 80372),
(1677, 120229, 'Stadium Australia', NULL, 80000),
(1698, 127224, 'Raymond James Stadium', 2, 75000),
(2105, 131243, 'FNB Stadium', NULL, 87600),
(2144, 134929, 'Rajamangala National Stadium', 2, 80000),
(2435, 152587, 'Stade des Martyrs', NULL, 80000),
(2436, 156312, 'San Siro', NULL, 90018),
(3060, 400123, 'Stade de France', NULL, 81338),
(3133, 425196, 'Melbourne Cricket Ground', NULL, 97474),
(5889, 978164, 'Sports Authority Field at Mile High', 2, 77160),
(5953, 1003845, 'Naghsh-e Jahan', 1, 75000),
(5954, 1003846, 'Yadegar-e Emam', 2, 71000),
(6530, 1301278, 'NSC Olympiyskyi', NULL, 70050),
(6735, 1301095, 'Luzhniki', 2, 81006),
(8412, 5620132, 'Guangdong Olympic Sports Centre', 2, 80012),
(8514, 5625181, 'Nasional Bukit Jalil', 2, 110000),
(8662, 5627556, 'National Olympic Stadium \'Bird\'s Nest\'', 2, 80000),
(9826, 7452614, 'Estadio Olímpico de Sevilla', NULL, 72000),
(11676, 8476343, 'Atatürk Olimpiyat Stadyumu', 2, 76092),
(12058, 8700726, 'Stadion München', 1, 75024),
(12097, 8826792, 'Estadio Monumental', 1, 80000),
(12724, 13201012, 'Grand Stade de Casablanca', 2, 80000),
(13917, 16031791, 'Wiener Prater Stadion', NULL, 92708),
(17075, 19141000, 'Estádio Nacional Mané Garrincha', 2, 72788),
(17323, 20032542, 'Bank of America Stadium', 3, 74113),
(17335, 20033734, 'Qualcomm Stadium', 2, 71283),
(17338, 20033737, 'FirstEnergy Stadium', 2, 73204),
(17339, 23017671, 'Borg El-Arab Stadium', NULL, 80000),
(17386, 20033738, 'M&T Bank Stadium', 2, 74320),
(17388, 20033740, 'SunLife Stadium', 3, 80120),
(17390, 20033742, 'Levi\'s Stadium', 3, 75000),
(17394, 20034500, 'Georgia Dome', 2, 75624),
(17397, 20034503, 'Alamo Dome', 2, 72000),
(19621, 29075067, 'Lusail Iconic Stadium', 2, 86250),
(27339, 47037578, 'Los Angeles Memorial Coliseum', 2, 93607),
(28837, 56000750, 'Croke Park', NULL, 82300),
(30439, 67015609, 'Nuevo Mestalla', NULL, 75000),
(33296, 72018535, 'NRG Stadium', 2, 71738),
(33297, 72018536, 'AT&T Stadium', 2, 105121),
(33333, 72022056, 'MetLife Stadium', 2, 82566),
(33663, 72038733, 'FedEx Field', 3, 91673),
(33668, 72047297, 'Mercedes-Benz Stadium', 2, 71000),
(37843, 96022210, '10-lecia', NULL, 71008);
SELECT id, fm_id, name, owner_type FROM `stadiums_test` WHERE `capacity` > '70000' ORDER BY `owner_type` DESC LIMIT 40 OFFSET 0;
SELECT id, fm_id, name, owner_type FROM `stadiums_test` WHERE `capacity` > '70000' ORDER BY `owner_type` DESC LIMIT 40 OFFSET 40;