1

我有以下数据库

表的表结构trains

CREATE TABLE IF NOT EXISTS `trains` (
    `id` mediumint(8) unsigned NOT NULL AUTO_INCREMENT,
    `train_no` varchar(5) COLLATE latin1_general_ci DEFAULT NULL,
    `train_name` varchar(50) COLLATE latin1_general_ci NOT NULL,
    `runsfrom` varchar(50) COLLATE latin1_general_ci NOT NULL,
    `SUN` varchar(3) COLLATE latin1_general_ci NOT NULL,
    `MON` varchar(3) COLLATE latin1_general_ci NOT NULL,
    `TUE` varchar(3) COLLATE latin1_general_ci NOT NULL,
    `WED` varchar(3) COLLATE latin1_general_ci NOT NULL,
    `THU` varchar(3) COLLATE latin1_general_ci NOT NULL,
    `FRI` varchar(3) COLLATE latin1_general_ci NOT NULL,
    `SAT` varchar(3) COLLATE latin1_general_ci NOT NULL,
    `DOE` date NOT NULL,
    PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci AUTO_INCREMENT=1912 ;

有这样的数据：

INSERT INTO `trains` VALUES (269, '12307', 'HWH JU  EXPRESS', 'HOWRAH JN', 'MON', 'TUE', 'WED', 'THU', 'FRI', 'SAT', 'SUN', '2013-03-24');
INSERT INTO `trains` VALUES (270, '12308', 'JU HWH SUPFAST', 'JODHPUR JN', 'MON', 'TUE', 'WED', 'THU', 'FRI', 'SAT', 'SUN', '2013-03-24');
INSERT INTO `trains` VALUES (381, '12461', 'MANDOR EXPRESS', 'DELHI', 'MON', 'TUE', 'WED', 'THU', 'FRI', 'SAT', 'SUN', '2013-03-24');
INSERT INTO `trains` VALUES (382, '12462', 'MANDOR EXPRESS', 'JODHPUR JN', 'MON', 'TUE', 'WED', 'THU', 'FRI', 'SAT', 'SUN', '2013-03-24');

表的表结构train_number

CREATE TABLE IF NOT EXISTS `train_number` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `train_no` varchar(5) NOT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=1912 ;

有这样的数据：

INSERT INTO `train_number` VALUES (269, '12307');
INSERT INTO `train_number` VALUES (270, '12308');
INSERT INTO `train_number` VALUES (381, '12461');

表的表结构train_schedule

CREATE TABLE IF NOT EXISTS `train_schedule` (
    `train_no` varchar(5) NOT NULL,
    `stn_code` varchar(20) NOT NULL,
    `stn_name` varchar(50) NOT NULL,
    `route_no` varchar(2) NOT NULL,
    `arr_time` varchar(5) NOT NULL,
    `dep_time` varchar(5) NOT NULL,
    `halt_time` varchar(5) NOT NULL,
    `distance` varchar(4) NOT NULL,
    `day` varchar(2) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

有这样的数据：

INSERT INTO `train_schedule` VALUES ('12307', 'HWH ', 'HOWRAH JN      ', '1', 'Sourc', '23:30', '', '0', '1');
INSERT INTO `train_schedule` VALUES ('12307', 'BWN ', 'BARDDHAMAN JN  ', '1', '00:35', '00:37', '2:00', '95', '2');
INSERT INTO `train_schedule` VALUES ('12307', 'ASN ', 'ASANSOL JN     ', '1', '01:52', '01:56', '4:00', '200', '2');
INSERT INTO `train_schedule` VALUES ('12307', 'DHN ', 'DHANBAD JN     ', '1', '03:05', '03:15', '10:00', '259', '2');

现在我想找到在特定日期找到两个车站之间的火车。所以我尝试了这个查询

SELECT distinct d1.train_no
FROM   train_schedule d1
INNER JOIN train_schedule d2 ON d2.train_no=d1.train_no
WHERE d1.stn_code = 'JU' and d2.stn_code = 'JP'

但它同时显示了从 JU 到 JP 以及从 JP 到 JU 的数据，因此它使结果加倍。

我想让这个查询只 在特定日期的一个方向上正确，因为它运行的天数也在数据库中给出

4

2 回答 2

0

如果我正确理解您的问题，要回答仅返回一个方向的部分，请尝试以下查询：

SELECT d1.*
FROM   train_schedule d1
INNER JOIN train_schedule d2 ON d2.train_no=d1.train_no
WHERE d1.stn_code = 'JU' and d2.stn_code = 'JP' 
   AND d1.distance < d2.distance

JU（出发）的距离总是小于 JP（到达）。

于 2013-04-15T06:46:28.363 回答
-1

而不是 sun...sat 你应该使用 1..7 并使值 boolean 或 tinyint

 SELECT distinct d1.train_no
 FROM   train_schedule d1 WHERE DAYOFWEEK(#yyyy-dd-mm#) = 1
 INNER JOIN train_schedule d2 ON d2.train_no=d1.train_no
 WHERE d1.stn_code = 'JU' and d2.stn_code = 'JP'

这应该工作

于 2013-04-15T07:25:43.060 回答