MySQL Select Where max date and max time

问题

I have this kind of table:

CREATE TABLE Buckets (
    id INT UNSIGNED AUTO_INCREMENT,
    checkDate DATE NOT NULL,
    checkTime TIME NOT NULL,
    accountId CHAR(13),
    costCenter VARCHAR(30),
    percentage DECIMAL(5,2),

    UNIQUE INDEX (checkDate, checkTime, accountId, costCenter),
    PRIMARY KEY (id)

)ENGINE=InnoDB;

There I have currently this kind of data:

1 2014-03-24 08:11:27 387909559196 72350 86.92
2 2014-03-24 08:11:27 387909559196 analytics 12.71
3 2014-03-24 08:11:27 387909559196 json-files 0.36
4 2014-03-24 08:11:27 387909559196 cloud 0.01
5 2014-03-25 08:11:27 387909559196 72350 86.92
6 2014-03-25 08:11:27 387909559196 analytics 12.71
7 2014-03-25 08:11:27 387909559196 json-files 0.36
8 2014-03-25 08:11:27 387909559196 cloud 0.01
9 2014-03-25 08:38:55 387909559196 72350 86.92
10 2014-03-25 08:38:55 387909559196 analytics 12.71
11 2014-03-25 08:38:55 387909559196 json-files 0.36
12 2014-03-25 08:38:55 387909559196 cloud 0.01

I would like to make Select which selects max date and then max time. In this case results should include only rows 9-12.

So far I have tried this kind of query, but unfortunately I'm not getting the results what I want:

SELECT b.id, b.checkDate, b.checkTime, b.AccountId, b.costCenter, b.percentage, c.id, c.name FROM Buckets b
JOIN CustomerAccounts ca ON (b.accountId= ca.linkedAccountId)
JOIN Customer c ON (ca.customerId = c.id)
WHERE checkDate = (SELECT max(checkDate) FROM Buckets)
AND checkTime = (SELECT max(checkTime) FROM Buckets)

回答1:

Try like this

SELECT * FROM
(
  SELECT b.id, b.checkDate, b.checkTime, b.AccountId, b.costCenter, b.percentage, c.id, c.name     
  FROM Buckets b JOIN CustomerAccounts ca ON (b.accountId= ca.linkedAccountId)
                 JOIN Customer c ON (ca.customerId = c.id)
) AS S JOIN 
(
  SELECT max(checkDate) AS MaxDate,max(checkTime) As MaxTime FROM Buckets
) AS T ON T.MaxDate = S.checkDate AND S.checkTime = T.MaxTime

来源：https://stackoverflow.com/questions/22629307/mysql-select-where-max-date-and-max-time

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