我有以下样本表。
CREATE TABLE IF NOT EXISTS `my_customer` (
`customer_id` int(11) NOT NULL AUTO_INCREMENT,
`customer_email` text NOT NULL,
PRIMARY KEY (`customer_id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=64 ;
INSERT INTO `my_customer` (`customer_id`, `customer_email`) VALUES
(4, 'muthu.d@test.in'),
(5, 'nsrirengan@test.in'),
(6, 'vinothini.k@test.in'),
(8, 'vinothini.k111@test.in'),
(63, 'sri.n321@test.in'),
(56, 'vesri.n@test.in'),
(57, 'veesri.n@test.in'),
(58, 'veeisri.n@test.in'),
(59, 'ren@test.in'),
(60, 'ren1@test.in'),
(61, 'nsrirengan123@test.in'),
(62, 'nsrirengan321@test.in'),
(53, 'sri.n@test.in'),
(54, 'royalrenga@test.in'),
(55, 'vesri@test.in');
CREATE TABLE IF NOT EXISTS `my_order` (
`orderid` int(11) NOT NULL AUTO_INCREMENT,
`ordergenerateid` varchar(20) NOT NULL,
`restaurant_id` int(11) NOT NULL,
`customer_id` int(11) NOT NULL,
`usertype` varchar(10) NOT NULL,
`customeremail` varchar(200) NOT NULL,
PRIMARY KEY (`orderid`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=152 ;
INSERT INTO `my_order` (`orderid`, `ordergenerateid`, `restaurant_id`, `customer_id`, `usertype`, `customeremail`) VALUES
(1, 'ORD0001', 3, 6, 'C', 'vinothini.k@test.in'),
(2, 'ORD0002', 1, 6, 'C', 'vinothini.k@test.in'),
(3, 'ORD0003', 3, 6, 'C', 'vinothini.k@test.in'),
(4, 'ORD0004', 3, 6, 'C', 'vinothini.k@test.in'),
(5, 'ORD0005', 3, 0, 'G', 'vinothini.k5555555@test.in'),
(6, 'ORD0006', 3, 6, 'C', 'vinothini.k@test.in'),
(7, 'ORD0007', 3, 6, 'C', 'vinothini.k@test.in'),
(8, 'ORD0008', 3, 6, 'C', 'vinothini.k@test.in'),
(9, 'ORD0009', 3, 6, 'C', 'vinothini.k@test.in'),
(10, 'ORD0010', 3, 6, 'C', 'vinothini.k@test.in'),
(11, 'ORD0011', 3, 6, 'C', 'vinothini.k@test.in'),
(12, 'ORD0012', 3, 6, 'C', 'vinothini.k@test.in'),
(13, 'ORD0013', 3, 6, 'C', 'vinothini.k@test.in'),
(14, 'ORD0014', 3, 6, 'C', 'vinothini.k@test.in'),
(15, 'ORD0015', 2, 3, 'C', 'sri.n@test.in'),
(16, 'ORD0016', 2, 3, 'C', 'sri.n@test.in'),
(17, 'ORD0017', 2, 3, 'C', 'sri.n@test.in'),
(18, 'ORD0018', 2, 3, 'C', 'sri.n@test.in'),
(19, 'ORD0019', 2, 3, 'C', 'sri.n@test.in'),
(20, 'ORD0020', 8, 3, 'C', 'sri.n@test.in'),
(21, 'ORD0021', 5, 3, 'C', 'sri.n@test.in'),
(22, 'ORD0022', 13, 3, 'C', 'sri.n@test.in'),
(23, 'ORD0023', 13, 3, 'C', 'sri.n@test.in'),
(24, 'ORD0024', 13, 3, 'C', 'sri.n@test.in'),
(25, 'ORD0025', 13, 3, 'C', 'sri.n@test.in'),
(26, 'ORD0026', 13, 3, 'C', 'sri.n@test.in'),
(27, 'ORD0027', 13, 3, 'C', 'sri.n@test.in'),
(28, 'ORD0028', 13, 3, 'C', 'sri.n@test.in'),
(29, 'ORD0029', 13, 3, 'C', 'sri.n@test.in'),
(30, 'ORD0030', 13, 3, 'C', 'sri.n@test.in'),
(31, 'ORD0031', 13, 3, 'C', 'sri.n@test.in'),
(32, 'ORD0032', 13, 3, 'C', 'sri.n@test.in'),
(33, 'ORD0033', 13, 3, 'C', 'sri.n@test.in'),
(34, 'ORD0034', 13, 3, 'C', 'sri.n@test.in'),
(35, 'ORD0035', 13, 3, 'C', 'sri.n@test.in'),
(36, 'ORD0036', 13, 3, 'C', 'sri.n@test.in'),
(37, 'ORD0037', 13, 3, 'C', 'sri.n@test.in'),
(38, 'ORD0038', 13, 3, 'C', 'sri.n@test.in'),
(39, 'ORD0039', 19, 3, 'C', 'sri.n@test.in'),
(40, 'ORD0040', 13, 3, 'C', 'sri.n@test.in'),
(41, 'ORD0041', 13, 3, 'C', 'sri.n@test.in'),
(42, 'ORD0042', 13, 3, 'C', 'sri.n@test.in'),
(43, 'ORD0043', 13, 3, 'C', 'sri.n@test.in'),
(44, 'ORD0044', 13, 3, 'C', 'sri.n@test.in'),
(45, 'ORD0045', 13, 3, 'C', 'sri.n@test.in'),
(46, 'ORD0046', 13, 3, 'C', 'sri.n@test.in'),
(47, 'ORD0047', 13, 3, 'C', 'sri.n@test.in'),
(48, 'ORD0048', 13, 3, 'C', 'sri.n@test.in'),
(49, 'ORD0049', 19, 3, 'C', 'sri.n@test.in'),
(51, 'ORD0051', 13, 3, 'C', 'sri.n@test.in'),
(52, 'ORD0052', 13, 3, 'C', 'sri.n@test.in'),
(53, 'ORD0053', 13, 3, 'C', 'sri.n@test.in'),
(54, 'ORD0054', 13, 10, 'G', 'sri.nas@test.in'),
(55, 'ORD0055', 13, 11, 'G', 'sri.nasqw@test.in'),
(56, 'ORD0056', 13, 12, 'G', 'sri.nqw@test.in'),
(57, 'ORD0057', 13, 13, 'G', 'sri.nas1123@test.in'),
(58, 'ORD0058', 13, 14, 'G', 'sri.nqw13@test.in'),
(59, 'ORD0059', 13, 15, 'G', 'sri.nas123@test.in'),
(60, 'ORD0060', 13, 16, 'G', 'sri.nas12345@test.in'),
(61, 'ORD0061', 13, 17, 'G', 'sri.nqw123@test.in'),
(62, 'ORD0062', 13, 18, 'G', 'sri.nas123111@test.in'),
(63, 'ORD0063', 13, 19, 'G', 'sri@test.in'),
(64, 'ORD0064', 13, 20, 'G', 'sri.nas111@test.in'),
(65, 'ORD0065', 13, 21, 'G', 'sri.nas12354klk@test.in'),
(66, 'ORD0066', 13, 22, 'G', 'sri.nas123879@test.in'),
(67, 'ORD0067', 13, 23, 'G', 'sri.nasasd@test.in'),
(68, 'ORD0068', 13, 24, 'G', 'sri.nasqwe@test.in'),
(69, 'ORD0069', 13, 25, 'G', 'sri.nas121212@test.in'),
(70, 'ORD0070', 13, 26, 'G', 'sri.nasqwqw@test.in'),
(71, 'ORD0071', 13, 27, 'G', 'sri.nqw321@test.in'),
(72, 'ORD0072', 13, 28, 'G', 'sri.nas123123@test.in'),
(73, 'ORD0073', 13, 3, 'C', 'sri.n@test.in'),
(74, 'ORD0074', 13, 3, 'C', 'sri.n@test.in'),
(75, 'ORD0075', 13, 3, 'C', 'sri.n@test.in'),
(76, 'ORD0076', 13, 3, 'C', 'sri.n@test.in'),
(77, 'ORD0077', 13, 3, 'C', 'sri.n@test.in'),
(78, 'ORD0078', 13, 3, 'C', 'sri.n@test.in'),
(79, 'ORD0079', 13, 3, 'C', 'sri.n@test.in'),
(121, 'ORD0121', 13, 52, 'G', 'sssri.n123123@test.in'),
(122, 'ORD0122', 13, 3, 'C', 'sri.n@test.in'),
(123, 'ORD0123', 13, 3, 'C', 'sri.n@test.in'),
(84, 'ORD0084', 13, 3, 'C', 'sri.n@test.in'),
(86, 'ORD0086', 13, 3, 'C', 'sri.n@test.in'),
(87, 'ORD0087', 13, 3, 'C', 'sri.n@test.in'),
(89, 'ORD0089', 13, 31, 'G', 'royalrenga@test.in'),
(90, 'ORD0090', 13, 32, 'G', 'nsri.n@test.in'),
(91, 'ORD0091', 13, 33, 'G', 'nnsri.n@test.in'),
(92, 'ORD0092', 13, 3, 'C', 'sri.n@test.in'),
(93, 'ORD0093', 13, 34, 'G', 'sssri.n@test.in'),
(94, 'ORD0094', 13, 35, 'G', 'qwsri.n@test.in'),
(95, 'ORD0095', 13, 36, 'G', 'snsri.n@test.in'),
(96, 'ORD0096', 13, 37, 'G', 'ncnsri.n@test.in'),
(97, 'ORD0097', 13, 38, 'G', 'nwnsri.n@test.in'),
(98, 'ORD0098', 13, 39, 'G', 'ncnasri.n@test.in'),
(99, 'ORD0099', 13, 40, 'G', 'ncnsasri.n@test.in'),
(100, 'ORD0100', 13, 41, 'G', 'ncqqnasri.n@test.in'),
(101, 'ORD0101', 13, 42, 'G', 'asdqazsri.nas123@test.in'),
(102, 'ORD0102', 13, 43, 'G', 'nacqqnasri.n@test.in'),
(103, 'ORD0103', 13, 3, 'C', 'sri.n@test.in'),
(104, 'ORD0104', 13, 3, 'C', 'sri.n@test.in'),
(105, 'ORD0105', 13, 3, 'C', 'sri.n@test.in'),
(106, 'ORD0106', 13, 3, 'C', 'sri.n@test.in'),
(107, 'ORD0107', 13, 3, 'C', 'sri.n@test.in'),
(108, 'ORD0108', 13, 0, 'G', 'sri.n@test.in'),
(109, 'ORD0109', 13, 3, 'C', 'sri.n@test.in'),
(110, 'ORD0110', 13, 3, 'C', 'sri.n@test.in'),
(111, 'ORD0111', 13, 44, 'G', 'qsw@test.in'),
(112, 'ORD0112', 13, 45, 'G', 'asdasd@test.in'),
(113, 'ORD0113', 13, 46, 'G', 'qweee@test.in'),
(114, 'ORD0114', 13, 47, 'G', 'qweqwe@test.in'),
(115, 'ORD0115', 13, 48, 'G', 'nsv123sri.n@test.in'),
(116, 'ORD0116', 13, 49, 'G', 'asdasdasd@test.in'),
(117, 'ORD0117', 13, 50, 'G', 'asdasdasdasd@test.in'),
(118, 'ORD0118', 13, 51, 'G', 'qwerew@test.in'),
(119, 'ORD0119', 13, 7, 'C', 'kvinocse86@test.in'),
(120, 'ORD0120', 13, 3, 'C', 'sri.n@test.in'),
(124, 'ORD0124', 13, 53, 'C', 'sri.n@test.in'),
(125, 'ORD0125', 13, 0, 'G', 'sri.n@test.in'),
(126, 'ORD0126', 13, 53, 'C', 'sri.n@test.in'),
(127, 'ORD0127', 13, 53, 'C', 'sri.n@test.in'),
(128, 'ORD0128', 13, 53, 'C', 'sri.n@test.in'),
(129, 'ORD0129', 13, 53, 'C', 'sri.n@test.in'),
(130, 'ORD0130', 13, 53, 'C', 'sri.n@test.in'),
(131, 'ORD0131', 13, 53, 'C', 'sri.n@test.in'),
(132, 'ORD0132', 13, 53, 'C', 'sri.n@test.in'),
(133, 'ORD0133', 13, 53, 'C', 'sri.n@test.in'),
(134, 'ORD0134', 13, 53, 'C', 'sri.n@test.in'),
(135, 'ORD0135', 13, 53, 'C', 'sri.n@test.in'),
(136, 'ORD0136', 13, 53, 'C', 'sri.n@test.in'),
(137, 'ORD0137', 13, 53, 'C', 'sri.n@test.in'),
(138, 'ORD0138', 13, 53, 'C', 'sri.n@test.in'),
(139, 'ORD0139', 13, 0, 'G', 'sri.n321@test.in'),
(140, 'ORD0140', 13, 53, 'C', 'sri.n123@test.in'),
(141, 'ORD0141', 13, 53, 'C', 'sri.n@test.in'),
(142, 'ORD0142', 13, 53, 'C', 'sri.n@test.in'),
(143, 'ORD0143', 13, 55, 'G', 'vesri@test.in'),
(144, 'ORD0144', 13, 56, 'G', 'vesri.n@test.in'),
(145, 'ORD0145', 13, 57, 'G', 'veesri.n@test.in'),
(146, 'ORD0146', 13, 58, 'G', 'veeisri.n@test.in'),
(147, 'ORD0147', 13, 59, 'G', 'ren@test.in'),
(148, 'ORD0148', 13, 60, 'G', 'ren1@test.in'),
(149, 'ORD0149', 13, 53, 'C', 'sri.n@test.in'),
(150, 'ORD0150', 13, 53, 'C', 'sri.n@test.in'),
(151, 'ORD0151', 13, 53, 'C', 'sri.n@test.in');
CREATE TABLE IF NOT EXISTS `my_restaurant` (
`restaurant_id` int(11) NOT NULL AUTO_INCREMENT,
`restaurant_name` varchar(100) NOT NULL,
PRIMARY KEY (`restaurant_id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=23 ;
INSERT INTO `my_restaurant` (`restaurant_id`, `restaurant_name`) VALUES
(1, 'Fuji Sushi'),
(2, 'Big Pete''s Pizza'),
(3, 'Vinos Pizza'),
(4, 'Wafaa and Mikes Cafe'),
(5, 'Fuji Sushi (San Marco Blvd)'),
(6, 'Midtown Deli + Cafe'),
(7, 'De Real Ting Cafe'),
(8, 'Alex Delicatessen'),
(9, 'Two Doors Down Restaurant'),
(10, 'Ginas Deli'),
(11, 'The Mudville Grille (Beach Blvd)'),
(12, 'Casbah Cafe'),
(13, 'Alexander Grill'),
(14, 'The Southern Grill'),
(15, 'Cool Moose Cafe'),
(16, 'Basil: Thai and Sushi'),
(17, 'Hot Wok'),
(18, 'China Joy'),
(19, 'Blu Diner'),
(21, 'New Test restaurant'),
(22, 'testing res');
我已经为客户用restauant完成了大部分订单的以下SQL。
SELECT o.customeremail AS custemail, o.restaurant_id, rest.restaurant_name, COUNT( o.customeremail ) AS totalordercount
FROM my_order AS o
INNER JOIN my_customer AS cust ON cust.customer_email = o.customeremail
INNER JOIN my_restaurant AS rest ON rest.restaurant_id = o.restaurant_id
WHERE o.orderid IS NOT NULL
GROUP BY o.restaurant_id
ORDER BY totalordercount DESC
我得到了这样的结果。
custemail restaurant_id restaurant_name totalordercount
sri.n@test.in 13 Alexander Grill 79
vinothini.k@test.in 3 Vinos Pizza 12
sri.n@test.in 2 Big Pete's Pizza 5
sri.n@test.in 19 Blu Diner 2
vinothini.k@test.in 1 Fuji Sushi 1
sri.n@test.in 8 Alex Delicatessen 1
sri.n@test.in 5 Fuji Sushi (San Marco Blvd) 1
SELECT *
FROM `my_order`
WHERE `restaurant_id` =13
AND `customeremail` = 'sri.n@test.in'
LIMIT 0 , 30
我从上面查询仅获得71行。但我的查询显示了第79行
sri.n@test.in 13 Alexander Grill 79
但我需要像这样的输出。
custemail restaurant_id restaurant_name totalordercount
sri.n@test.in 13 Alexander Grill 71
vinothini.k@test.in 3 Vinos Pizza 12
sri.n@test.in 2 Big Pete's Pizza 5
sri.n@test.in 19 Blu Diner 2
vinothini.k@test.in 1 Fuji Sushi 1
sri.n@test.in 8 Alex Delicatessen 1
sri.n@test.in 5 Fuji Sushi (San Marco Blvd) 1
提前致谢
答案 0 :(得分：0)
首先，您通过尝试在餐馆汇总的结果集中显示客户电子邮件来滥用pernicious nonstandard MySQL extension to GROUP BY。您滥用此操作会导致结果集包含任意的custemail值。
其次，这个简单的查询显示亚历山大烧烤有121个订单。您声称只有71个似乎是不正确的。
SELECT COUNT(*), o.restaurant_id, r.restaurant_name
FROM my_order AS o
LEFT JOIN my_restaurant AS r ON o.restaurant_id = r.restaurant_id
GROUP BY o.restaurant_id, r.restaurant_name
第三，有很多订单的customer_id在客户表中找不到。您正在使用INNER JOIN，因此您的查询正在下降而不计算这些订单。 LEFT JOIN将恢复丢失的记录。但是，你仍然没有使用那个JOIN的结果。
第四，您的WHERE o.orderid IS NOT NULL子句毫无意义：该列是主键。
尝试此查询，省略my_customer表JOIN：
SELECT o.restaurant_id,
rest.restaurant_name,
COUNT( DISTINCT o.customer_id ) AS distinctcustomercount,
COUNT( * ) AS totalordercount
FROM my_order AS o
LEFT JOIN my_restaurant AS rest ON rest.restaurant_id = o.restaurant_id
GROUP BY o.restaurant_id, rest.restaurant_name /* fix GROUP BY misuse */
ORDER BY COUNT( * ) DESC, rest.restaurant_name
我认为这对你有用。它完全指定GROUP BY，它在只有一个订单的餐馆行中进行某种排序。
答案 1 :(得分：0)
我认为您正在寻找在客户表中存在的客户电子邮件的餐馆访问次数。其他数字只是证明是正确的，因为71岁的其他人只访问了一个餐厅。 如果您希望每个餐厅都有客户，则需要将客户电子邮件添加到组中。
SELECT o.customeremail AS custemail,
o.restaurant_id, rest.restaurant_name, COUNT(o.customeremail ) AS totalordercount
FROM my_order AS o
INNER JOIN my_customer AS cust ON cust.customer_email = o.customeremail
INNER JOIN my_restaurant AS rest ON rest.restaurant_id = o.restaurant_id
GROUP BY o.restaurant_id, o.customeremail
ORDER BY totalordercount DESC
我的回答与Ollie相同，只是我让客户加入，我认为需要在场才能获得预期的结果。