Question

我有三个表：tblFuel，tblDoXang，tblDrivingTime2。现在我想在tblFuel中显示满足tblDrivingTime2中某些条件的fuelLevel字段，如果在特定时间（基于tblFuel中的时间戳），如果我检查在tblDoXang中添加燃料操作，我必须插入它（nhienLieu字段在tblDoXang ）报告显示上面的fuelLevel。目标很可能是： tblFuel：

timestamp     fuelLevel
123456         10
123467         8
123478         50
123489         20

tblDrivingTime2：

这将打印：

10
50
20

现在我们检查是否 tblDoXang

thoiGian      nhienLieu
123457        15
123466        10

它将插入上面的结果，最后，结果将是：

我写了两个单独的查询来执行这些任务：

SELECT distinct from_unixtime(F.timestamp), F.fuelLevel FROM gtse.tblFuel F 
INNER JOIN gtse.tblDrivingTime2 D 
ON D.accountID = F.accountID and D.deviceID = F.deviceID 
where (from_unixtime(F.timestamp) between '2014-10-10 10:52:02' and '2014-10-30 10:52:02')
and F.accountID = 'vinhnghia'
and F.deviceID = '14C-00263'
and (D.reportType = '2' or D.reportType = '3')
and F.timestamp = D.stopTime
order by F.timestamp asc;

这将在第一次（10,50和20）打印结果，并且：

SELECT distinct from_unixtime(D.thoiGian), D.nhienLieu
FROM gtse.tblDoXang D
inner join gtse.tblFuel F
on D.accountID = F.accountID and D.deviceID = F.deviceID
where D.accountID = 'vinhnghia' and D.deviceID = '14C-00263'
and D.thoiGian <= F.timestamp
order by D.thoiGian asc;

将显示值（15,10）。我的问题是如何加入两个查询以显示最终结果？：

Answer 1

也许您可以尝试使用UNION子句：

( 
    SELECT distinct 
       from_unixtime(F.timestamp) As col_1, 
       F.fuelLevel as col_2
    FROM 
       gtse.tblFuel F 
       INNER JOIN gtse.tblDrivingTime2 D 
                  ON D.accountID = F.accountID 
                     and D.deviceID = F.deviceID
    where 
       (from_unixtime(F.timestamp) between '2014-10-10 10:52:02' and '2014-10-30 10:52:02') 
       and F.accountID = 'vinhnghia' 
       and F.deviceID = '14C-00263' 
       and (D.reportType = '2' or D.reportType = '3') 
       and F.timestamp = D.stopTime 
    order by 
       F.timestamp asc
)
UNION
(
    SELECT distinct 
       from_unixtime(D.thoiGian) as col_1, 
       D.nhienLieu as col_2 
    FROM 
       gtse.tblDoXang D 
       inner join gtse.tblFuel F 
                  on D.accountID = F.accountID 
                     and D.deviceID = F.deviceID 
    where 
       D.accountID = 'vinhnghia' 
       and D.deviceID = '14C-00263' 
       and D.thoiGian <= F.timestamp 
    order by 
       D.thoiGian asc;
)

我希望我理解得很好，这可能会有所帮助。

在MySQL中加入三个已完成的表

1 个答案: