我读了几篇关于这个的文章:Select max date, then max time这似乎最有帮助，但我看不到实现它的方法。
有五张 table 。我加入他们。我只需要从第一个表中选择日期和时间最长的一行，从第二个表中选择相同的行，然后将其余的加入其他值。使用我编写的代码，我得到多行。看来时间选择不对。
可以用子查询中的子查询来完成。我试过这样的事情:
SELECT * from table1
INNER JOIN table2 ON table1.date = table2.date AND table1.gm = table2.gm
INNER JOIN table3 ON table2.gm = table3.gm ...
WHERE table3.date = :date AND table4.date = :date ...
AND table1.date IN(
SELECT MAX(table1.date) FROM table1 WHERE table1.time IN(
SELECT MAX(table1.time) FROM table1
)
)
AND table2.date IN(
SELECT MAX(table2.date) FROM table1 WHERE table2.time IN(
SELECT MAX(table2.time) FROM table2 )
)
ORDER BY table1.id
问题是: 如何在加入所有这些日期最高且该日期时间最高的位置后获得单行？ 谢谢!
编辑:我对此感到抱歉。我忘了说我需要与表(gm 列)中的特定值相关的最大日期的最大时间。所以这是一行(在示例中我给出的是 table1.gm 和 table2.gm ...)，每个 .gm 值中的每一个在每个表中都是相同的，而不仅仅是一行。 Nick 和 Salim 提供的解决方案有效，但我没有解决问题。
编辑:已解决!在实现 Nick 的解决方案后，我只需要添加 GROUP BY cntrs_reper.gm_company_no，cntrs_reper.date。 就是这样。对于一个表中的每一行都具有来自其他人的最高日期和时间!!感谢大家。
编辑。如果这可以帮助这是完整的查询:
SELECT cntrs_gm.gm_company_no AS company_c_g,
bns_gms.ded_bns AS ded_bns_gms,
bns_gms.no_ded_bns AS no_ded_bns_gms,
bns_gms.wag_ded_bns AS wag_ded_bns_gms,
cntrs_gm.cur_credit AS cur_credit_c_g,
cntrs_gm.cdrop AS cdrop_c_g,
cntrs_gm.total_jp AS total_jp_c_g,
cntrs_gm.games AS games_c_g,
cntrs_gm.wgames AS wgames_c_g,
cntrs_gm.doors AS doors_c_g,
cntrs_gm.power AS power_c_g,
cntrs_gm.total_in AS total_in_c_g,
cntrs_gm.total_out AS total_out_c_g,
cntrs_gm.total_acc AS total_acc_c_g,
cntrs_gm.total_bet AS total_bet_c_g,
cntrs_gm.total_win AS total_win_c_g,
cntrs_gm.total_bonus AS total_bonus_c_g,
cntrs_gm.date AS date_c_g,
cntrs_reper.gm_company_no AS company_reper,
bns_reper.ded_bns AS ded_bns_reper,
bns_reper.no_ded_bns AS no_ded_bns_reper,
bns_reper.wag_ded_bns AS wag_ded_bns_reper,
cntrs_reper.cur_credit AS cur_credit_reper,
cntrs_reper.cdrop AS cdrop_reper,
cntrs_reper.total_jp AS total_jp_reper,
cntrs_reper.games AS games_reper,
cntrs_reper.wgames AS wgames_reper,
cntrs_reper.doors AS doors_reper,
cntrs_reper.power AS power_reper,
cntrs_reper.total_in AS total_in_reper,
cntrs_reper.total_out AS total_out_reper,
cntrs_reper.total_acc AS total_acc_reper,
cntrs_reper.total_bet AS total_bet_reper,
cntrs_reper.total_win AS total_win_reper,
cntrs_reper.total_bonus AS total_bonus_reper,
cntrs_reper.date AS date_reper,
cntrs_reper.time AS time_reper,
bns_reper.time AS time_c_g,
gms_cfg.gm_no AS machine_id,
gms_cfg.denom_cin AS machine_cin
FROM bns_gms
INNER JOIN cntrs_gm
ON bns_gms.gm_company_no = cntrs_gm.gm_company_no AND bns_gms.date = cntrs_gm.date
INNER JOIN bns_reper
ON cntrs_gm.gm_company_no = bns_reper.gm_company_no
INNER JOIN cntrs_reper
ON bns_reper.gm_company_no = cntrs_reper.gm_company_no AND bns_reper.date = cntrs_reper.date
INNER JOIN gms_cfg
ON cntrs_reper.gm_company_no = gms_cfg.gm_no
WHERE bns_reper.date IN(
SELECT MAX(DATE(bns_reper.date)) FROM bns_reper WHERE bns_reper.time IN(
SELECT MAX(TIME(bns_reper.time)) FROM bns_reper
)
)
AND cntrs_reper.date IN(
SELECT MAX(DATE(cntrs_reper.date)) FROM cntrs_reper WHERE cntrs_reper.time IN(
SELECT MAX(TIME(cntrs_reper.time)) FROM cntrs_reper
)
)
ORDER BY cntrs_gm.gm_company_no
数据库示例
最佳答案
您当前查询的问题是它将选择所有行，其中 table1.date 是出现最高时间的最新日期，可能不止一个，例如对于诸如
之类的数据id date time
1 2018-03-30 18:40
2 2018-03-31 12:20
3 2018-03-31 19:20
您的WHERE 子句:
table1.date IN(
SELECT MAX(table1.date) FROM table1 WHERE table1.time IN(
SELECT MAX(table1.time) FROM table1
)
将选择 id=2 和 id=3 的行，因为它们都有 date = '2018-03-31'当最大时间出现时。
你想要做的是选择最晚日期的行，你可以使用它
table1.date = (SELECT MAX(date) FROM table1) AND
table1.time = (SELECT MAX(time) FROM table1 WHERE date = (SELECT(MAX(date) FROM table1))
通过使用别名，可以简化(因为我们已经知道 table1.date = MAX(date) FROM table1)
table1.date = (SELECT MAX(date) FROM table1) AND
table1.time = (SELECT MAX(time) FROM table1 AS t1 WHERE t1.date = table1.date)
关于mysql - 如何在该日期内选择日期和时间？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49602990/