SQL仅选择最近5分钟的记录

Question

I want to get the records from last 5 minutes. I am currently using this code, which I got from this site:

select * from table where timestamp between curtime() and timestamp(date_sub(now(), interval 5 minute))

But it doesn't work for me, it returns all my records at intervals of 5 minutes. For example, I'll have several records with a timestamp at 2014-07-30 15:40:02, then I'll get a 5 minute gap and get several records with a time stamp of 2014-07-30 15:45:02.

Answer 1

This is your where clause:

where timestamp between curtime() and timestamp(date_sub(now(), interval 5 minute))

In this case, the first bound is larger than the second, because you are subtracting 5 minutes from the current time. This actually should not match anything, because:

where x between y and y - 5

should always return an empty set. The bounds are in order. Perhaps swapping them will help:

where timestamp between timestamp(date_sub(now(), interval 5 minute)) and curtime()

However, if you don't have future timestamps, just do:

where timestamp >= timestamp(date_sub(now(), interval 5 minute))

Answer 2

select * from table where timestamp >= timestamp(date_sub(now(), interval 5 minute))

Answer 3

尝试使用：

read=("""select * from table where timestamp >= timestamp(date_sub(now(), interval 5 minute))""")

Answer 4

select * from table where timestamp between curtime() and DateADD(minute, -5, curtime());