MYSQL:
1、报表需要展示连续每天的数据，但业务数据可能是间断的，故关联dim_date表，使日期连续
CREATE TABLE `dim_date` (
`date_key` int(11) NOT NULL,
`date_value` date DEFAULT NULL,
`week_in_year` int(11) DEFAULT NULL,
`week_in_month` int(11) DEFAULT NULL,
`month_number` int(11) DEFAULT NULL,
`quarter_number` int(11) DEFAULT NULL,
`day_in_year` int(11) DEFAULT NULL,
`day_in_month` int(11) DEFAULT NULL,
`year` int(11) DEFAULT NULL,
`month` int(11) DEFAULT NULL,
`day` int(11) DEFAULT NULL,
PRIMARY KEY (`date_key`),
KEY `date_value_idx` (`date_value`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
2、动态拼接年月日、然后分组
SELECT
<if test="type == 1">
DATE(CONCAT(d.YEAR, '-', d.MONTH, '-', d.DAY))
</if>
<if test="type == 2">
DATE(CONCAT(d.YEAR, '-', d.MONTH, '-1'))
</if>
<if test="type == 3">
DATE(CONCAT(d.YEAR, '-1-1'))
</if>
<if test="type == 4">
DATE(CONCAT(d.YEAR, '-', d.MONTH, '-', d.DAY))
</if>
AS statdate,
SUM(a.order_num) AS order_num,
SUM(a.amount) AS amount,
SUM(a.validincome) AS validincome
FROM
dim_date d LEFT JOIN s_orderscount_day a on d.date_value = a.stat_date
<if test="fcId=='' and groupId==null">
AND a.finance_category_id = -1
</if>
<if test="fcId!='' or groupId!=null">
AND a.finance_category_id != -1
</if>
<if test="channel != null and channel != '' ">
AND a.sale_channel= #{channel}
</if>
<if test="fcId != null and fcId != ''">
AND FIND_IN_SET(a.finance_category_id, #{fcId})
</if>
<if test="fcId!='' or groupId!=null">
LEFT JOIN products p
ON
a.finance_category_id = p.oldid and a.product_group_id = p.groupid
</if>
<if test="groupId != null and groupId != '' ">
AND a.finance_category_id != -1
AND p.groupid = #{groupId}
</if>
WHERE 1=1
AND d.date_value <![CDATA[>=]]> #{startTime}
AND d.date_value <![CDATA[<=]]> #{endTime}
GROUP BY
statdate