我个人觉得我给这两个查询的条件都一样,为什么他们会产生不同的结果。虽然我认为他们应该产生相同的结果。我只是不了解这种异常的性质。请给我解释一下。两个查询之间有什么区别
SELECT
MIN(EventID)
FROM
[3rdi_Events]
WHERE
EventID IN (
SELECT DISTINCT
EventId
FROM
[3rdi_EventDates]
WHERE
EventDate Between '2/9/2011' AND '3/11/2012'
)
GROUP BY
EventTypeId
和
SELECT
EventId
FROM
[3rdi_Events] AS E
WHERE
E.EventID IN (
SELECT
min(EventId)
FROM
[3rdi_Events]
GROUP BY
EventTypeId
)
AND
E.EventID IN (
SELECT DISTINCT
EventId
FROM
[3rdi_EventDates]
WHERE
EventDate Between'2/9/2011' AND '3/11/2012'
)