MySQL按时间统计每个小时记录数
方案1：
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7
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SELECT
@rownum := @rownum + 1
AS
ID,
CONCAT((
CASE
WHEN
t.
hour
= 24
THEN
0
ELSE
t.
hour
END
),
':00:00'
)
AS
TIME
,
COUNT
(*)
AS
COUNT
FROM
(
SELECT
id,
HOUR
(DATE_FORMAT(createtime,
'%H:%i:%s'
))+1
AS
HOUR
FROM
baby
WHERE
DATE_FORMAT(createtime,
'%Y-%m-%d'
)=
'2016-10-16'
) t,
(
SELECT
@rownum := 0) r
GROUP
BY
TIME
ORDER
BY
ID
//这个计数, 是LESS THAN
TIME
的计数方法, 即11:xx:xx的记录是记到12:00:00下面的, 而不是11:00:00;
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上面的修改
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5
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SELECT
@rownum := @rownum + 1
AS
ID,
CONCAT((
CASE
WHEN
t.
hour
= 24
THEN
0
ELSE
t.
hour
END
),
''
)
AS
TIME
,
COUNT
(*)
AS
COUNT
FROM
(
SELECT
id,
HOUR
(DATE_FORMAT(createtime,
'%H:%i:%s'
))
AS
HOUR
FROM
baby
WHERE
DATE_FORMAT(createtime,
'%Y-%m-%d'
)=
'2016-10-16'
) t,
(
SELECT
@rownum := 0) r
GROUP
BY
TIME
ORDER
BY
ID
|
方案2
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1
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SELECT
LEFT
( createtime, 13 ) ,
COUNT
( * )
FROM
baby
WHERE
DATE_FORMAT(createtime,
'%Y-%m-%d'
)=
'2016-10-16'
GROUP
BY
LEFT
( createtime, 13 )
|
如果当前小时无数据目前无法返回0 ！ 不知道怎么处理了