Question

我有以下查询

select dc.dateasdate as 'Date', count(Practice) as 'Total Enquiries', dp.practice, de.Origin
from dim.Practice dp
    left join fact.enquiry fe on fe.PracticeSKey = dp.PracticeSKey
        left join dim.EnquiryOrigin de on de.EnquiryOriginSKey = fe.EnquiryOriginSKey and de.Origin = 'Web Enquiry'
            left join dim.Calendar dc on dc.CalendarSKey = fe.EnquiryCreatedSKey
                where dc.dateasdate = '2016-04-03' 
group by dc.dateasdate , de.Origin,practice
order by dc.dateasdate ,Practice

当有Practice时，它不会显示。

任何人都可以帮助我吗？我已经坚持了几天。

Answer 1

WHERE条件有效地将LEFT JOIN变为INNER JOIN。您应该将条件放在最后LEFT JOIN：

中

SELECT
    dc.dateasdate AS 'Date',
    COUNT(Practice) AS 'Total Enquiries',
    dp.practice,
    de.Origin
FROM dim.Practice dp
LEFT JOIN fact.enquiry fe
    ON fe.PracticeSKey = dp.PracticeSKey
LEFT JOIN dim.EnquiryOrigin de
    ON de.EnquiryOriginSKey = fe.EnquiryOriginSKey
    AND de.Origin = 'Web Enquiry'
LEFT JOIN dim.Calendar dc
    ON dc.CalendarSKey = fe.EnquiryCreatedSKey
    AND dc.dateasdate = '2016-04-03'
GROUP BY
    dc.dateasdate,
    de.Origin,
    practice
ORDER BY dc.dateasdate, Practice

没有结果时计数显示0

1 个答案: