Question

CREATE TABLE IF NOT EXISTS `accesscards` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `department` varchar(255) NOT NULL,
    `name` varchar(255) NOT NULL,
    `entrydates` datetime NOT NULL, PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;

INSERT INTO `accesscards` (`id`, `department`, `name`, `entrydates`) VALUES
(1, 'test', 't1', '2013-12-06 16:10:00'),
(2, 'test', 't1', '2013-12-06 15:10:00'),
(3, 'test', 't1', '2013-12-07 15:11:00'),
(4, 'test', 't1', '2013-12-07 15:24:00'),
(5, 'test', 't2', '2013-12-06 16:10:00'),
(6, 'test', 't2', '2013-12-06 16:25:00'),
(7, 'test', 't2', '2013-12-07 15:59:00'),
(8, 'test', 't2', '2013-12-07 16:59:00');

以上是我的查询，我想为每个人获取每天的记录。并且该记录应该具有当天的最小日期时间。我需要该日期时间的整个记录

我的预期输出here

我尝试使用

SELECT id, MIN(entrydates) FROM accesscards WHERE 1=1 AND name!='' GROUP BY DATE(entrydates) ORDER BY id

但对于't1'，我得到了id = 1和第一行的入门日期。

请帮帮我。如果重复，则提供链接。

Answer 1

SELECT a1.*
FROM accesscards a1
JOIN (SELECT name, MIN(entrydates) mindate
      FROM accesscards
      WHERE name != ''
      GROUP BY name, date(entrydates)) a2
ON a1.name = a2.name AND a1.entrydates = a2.mindate

DEMO

Answer 2

如果您使用的是mysql：GROUP_CONCAT和SUBSTRING_INDEX

SELECT 
  DATE(entrydates) AS grouped_date,
  GROUP_CONCAT(id ORDER BY entrydates ASC SEPARATOR ',') AS id_ordered_list,
  SUBSTRING_INDEX(GROUP_CONCAT(id ORDER BY entrydates ASC), ',', 1) AS min_id_for_day
FROM 
  accesscards 
WHERE 
  1=1 AND name!='' 
GROUP BY 
  DATE(entrydates)

如果您需要显示除id以外的其他字段，请将其添加到您选择：

  SUBSTRING_INDEX(GROUP_CONCAT(YOUR_FIELDNAME_HERE ORDER BY entrydates ASC), ',', 1) AS min_YOUR_FIELDNAME_for_day

在http://sqlfiddle.com/#!2/a2671/13

播放

使用新数据更新问题后： http://sqlfiddle.com/#!2/a2671/20

SELECT 
  DATE(entrydates) AS grouped_date,
  SUBSTRING_INDEX(GROUP_CONCAT(id ORDER BY entrydates ASC), ',', 1) AS min_id_for_day,
  department,
  name,
  SUBSTRING_INDEX(GROUP_CONCAT(entrydates ORDER BY entrydates ASC), ',', 1) AS min_entrydate_for_day
FROM 
  accesscards 
WHERE 
  1=1 AND name!='' 
GROUP BY 
  name,DATE(entrydates) 
ORDER BY entrydates

Answer 3

试试这个肯定会帮到你

select id,department,name,entrydates from accesscards where entrydates in (select min(entrydates) from accesscards group by to_char(entrydates,'dd-Mon-yyyy')) order by id;

获取每个人每天最小日期时间的记录

3 个答案: