mysql 实现时统计 hql

DATE_FORMAT(date,format)
根据format字符串格式化date值。下列修饰符可以被用在format字符串中：
%M 月名字(January……December)
%W 星期名字(Sunday……Saturday)
%D 有英语前缀的月份的日期(1st, 2nd, 3rd, 等等。）
%Y 年, 数字, 4 位
%y 年, 数字, 2 位
%a 缩写的星期名字(Sun……Sat)
%d 月份中的天数, 数字(00……31)
%e 月份中的天数, 数字(0……31)
%m 月, 数字(01……12)
%c 月, 数字(1……12)
%b 缩写的月份名字(Jan……Dec)
%j 一年中的天数(001……366)
%H 小时(00……23)
%k 小时(0……23)
%h 小时(01……12)
%I 小时(01……12)
%l 小时(1……12)
%i 分钟, 数字(00……59)
%r 时间,12 小时(hh:mm:ss [AP]M)
%T 时间,24 小时(hh:mm:ss)
%S 秒(00……59)
%s 秒(00……59)
%p AM或PM
%w 一个星期中的天数(0=Sunday ……6=Saturday ）
%U 星期(0……52), 这里星期天是星期的第一天
%u 星期(0……52), 这里星期一是星期的第一天
%% 一个文字“%”。

所有的其他字符不做解释被复制到结果中。

mysql> select DATE_FORMAT('1997-10-04 22:23:00', '%W %M %Y');
-> 'Saturday October 1997'
mysql> select DATE_FORMAT('1997-10-04 22:23:00', '%H:%i:%s');
-> '22:23:00'
mysql> select DATE_FORMAT('1997-10-04 22:23:00',
'%D %y %a %d %m %b %j');
-> '4th 97 Sat 04 10 Oct 277'
mysql> select DATE_FORMAT('1997-10-04 22:23:00',
'%H %k %I %r %T %S %w');
-> '22 22 10 10:23:00 PM 22:23:00 00 6'


, '%Y %m'

Sql代码
FROM CUSTOMERS as customers
FROM CUSTOMERS as customers节 10.02 Where子句
(a) 比较表达式Sql代码
FROM CUSTOMERS as customers WHERE customers.id=1
FROM CUSTOMERS as customers WHERE customers.amount between 1 and 10
FROM CUSTOMERS as customers WHERE customers.amount >100
FROM CUSTOMERS as customers WHERE customers.email in ('foo@bar','bar@foo')
FROM CUSTOMERS as customers WHERE customers.email IS NULL
FROM CUSTOMERS as customers WHERE customers.email IS NOT NULL
FROM CUSTOMERS as customers WHERE customers.email LIKE '@%'
FROM CUSTOMERS as customers WHERE customers.id=1
FROM CUSTOMERS as customers WHERE customers.amount between 1 and 10
FROM CUSTOMERS as customers WHERE customers.amount >100
FROM CUSTOMERS as customers WHERE customers.email in ('foo@bar','bar@foo')
FROM CUSTOMERS as customers WHERE customers.email IS NULL
FROM CUSTOMERS as customers WHERE customers.email IS NOT NULL
FROM CUSTOMERS as customers WHERE customers.email LIKE '@%'HQL 操作符

HQL 常用操作符
描述

.
导航路径表达式操作符

+,-
一元正负号

*,/
乘除法

+,-
加减法

=,<>,<,>,>=,<=,[NOT]BETWEEN[NOT] LIKE,[NOT] IN,IS [NOT] NULL,IS [NOT] EMPTY
二元比较操作符



NOT,AND,OR
逻辑操作符

HQL操作符
(b) HQL常用函数
Sql代码
FROM User u where lower(u.email) = '[email protected]' --小写
FROM User u where lower(u.email) = '[email protected]' --大写
FROM User u where concat(u.firstname,u.lastname) like 'G% K%' --拼接字符串
FROM User u where size(u.bids) > 3 --集合大小
FROM User u where lower(u.email) = '[email protected]' --小写
FROM User u where lower(u.email) = '[email protected]' --大写
FROM User u where concat(u.firstname,u.lastname) like 'G% K%' --拼接字符串
FROM User u where size(u.bids) > 3 --集合大小HQL 函数

HQL 常用操作符
描述

UPPER(s),LOWER(s)
大小写

CONCAT(s1,s2)
连接字符串

SUBSTRING(s,offset,length)
取子串

TRIM()
去空格

LENGTH(s)
长度

LOCATE(search,s,offset)
搜索位置

ABS(n),SQRT(n),MOD(dividend,divisor)
绝对值，开方，除法

SIZE
大小写

BIT_LENGTH(s)
位数

CUTTENT_DATE()
当前时间

CURRENT_TIME()

CURRENT_TIMESTAMP()

SECOND(d)
获取时间的不同部分

MINUTE(d)

HOUR(d)

DAY(d)

MONTH(d)

YEAR(d)

CAST(t as TYPE)
类型转换

HQL函数
节 10.03 Order表达式
Sql代码
FROM CUSTOMERS as customers WHERE customers.id=1
ORDER BY customers.id FROM CUSTOMERS as customers
ORDER BY customers.lastname asc,firstname asc
FROM CUSTOMERS as customers WHERE customers.id=1
ORDER BY customers.id FROM CUSTOMERS as customers
ORDER BY customers.lastname asc,firstname asc
节 10.04 投影查询
Sql代码
SELECT user.user

name,user.password FROM UserInfo user
SELECT user.username,user.password FROM UserInfo user
注：1、在使用Select子句查询时，要给表对象起一个别名。
2、查询出的结果集是一个Object[]数组。

实现代码：

select count(*),p.createDate,DATE_FORMAT(p.createDate, '%Y-%m-%d %H :00:00') from user p group by DATE_FORMAT(p.createDate, '%W %M %Y %H') order by date(p.createDate) asc

运行结果：