如何限制查询结果占MySQL总结果数的百分比?
How to limit query results by a percentage of the total number of results in MySQL?
下面mysql问题returns只有前10行。我怎样才能将它们限制在全部的 10%?
SELECT page,
poso,
diff
FROM (SELECT page,
Count(*) AS poso,
( Sum(Date(timestamp) = Curdate()) - Sum(
Date(timestamp) = Date_sub(Curdate(),
INTERVAL 1 day)) )
diff
FROM `behaviour`
WHERE Date(timestamp) >= Date_sub(Curdate(), INTERVAL 1 day)
GROUP BY page
ORDER BY ( Sum(Date(timestamp) = Curdate()) - Sum(
Date(timestamp) = Date_sub(Curdate(),
INTERVAL 1 day))
) DESC
LIMIT 10) AS u
ORDER BY diff DESC
改编自the answer to the duplicate question:
SELECT page,
poso,
diff
FROM (
SELECT *,
@counter := @counter + 1 AS counter
FROM (select @counter:=0) AS initvar,
(SELECT page,
Count(*) AS poso,
( Sum(Date(timestamp) = Curdate()) - Sum(
Date(timestamp) = Date_sub(Curdate(),
INTERVAL 1 day)) )
diff
FROM `behaviour`
WHERE Date(timestamp) >= Date_sub(Curdate(), INTERVAL 1 day)
GROUP BY page
ORDER BY ( Sum(Date(timestamp) = Curdate()) - Sum(
Date(timestamp) = Date_sub(Curdate(),
INTERVAL 1 day))
) DESC) AS u
) AS v
WHERE counter <= 10/100 * @counter
ORDER BY diff DESC;
下面mysql问题returns只有前10行。我怎样才能将它们限制在全部的 10%?
SELECT page,
poso,
diff
FROM (SELECT page,
Count(*) AS poso,
( Sum(Date(timestamp) = Curdate()) - Sum(
Date(timestamp) = Date_sub(Curdate(),
INTERVAL 1 day)) )
diff
FROM `behaviour`
WHERE Date(timestamp) >= Date_sub(Curdate(), INTERVAL 1 day)
GROUP BY page
ORDER BY ( Sum(Date(timestamp) = Curdate()) - Sum(
Date(timestamp) = Date_sub(Curdate(),
INTERVAL 1 day))
) DESC
LIMIT 10) AS u
ORDER BY diff DESC
改编自the answer to the duplicate question:
SELECT page,
poso,
diff
FROM (
SELECT *,
@counter := @counter + 1 AS counter
FROM (select @counter:=0) AS initvar,
(SELECT page,
Count(*) AS poso,
( Sum(Date(timestamp) = Curdate()) - Sum(
Date(timestamp) = Date_sub(Curdate(),
INTERVAL 1 day)) )
diff
FROM `behaviour`
WHERE Date(timestamp) >= Date_sub(Curdate(), INTERVAL 1 day)
GROUP BY page
ORDER BY ( Sum(Date(timestamp) = Curdate()) - Sum(
Date(timestamp) = Date_sub(Curdate(),
INTERVAL 1 day))
) DESC) AS u
) AS v
WHERE counter <= 10/100 * @counter
ORDER BY diff DESC;