MySQL按小时查询数据没有的补0代码示例

作者:袖梨 2022-06-29

本篇文章小编给大家分享一下MySQL按小时查询数据没有的补0代码示例,文章代码介绍的很详细,小编觉得挺不错的,现在分享给大家供大家参考,有需要的小伙伴们可以来看看。

需求背景

一个统计接口,前端需要返回两个数组,一个是0-23的小时计数,一个是各小时对应的统计数。

思路 直接使用group by查询要统计的表,当某个小时统计数为0时,会没有该小时分组。思考了一下,需要建立辅助表,只有一列小时,再插入0-23共24个小时

CREATE TABLE hours_list (
 hour int NOT NULL PRIMARY KEY
)

先查小时表,再做连接需要查的表,即可将没有统计数的小时填充上0。这里由于需要查多个表中,create_time在每个小时区间内、且SOURCE_ID等于查询条件的统计之和,所以UNION ALL了多张表

	SELECT
			 t.HOUR,
			 sum(t.HOUR_COUNT) hourCount
			FROM
    (SELECT
     hs. HOUR AS HOUR,
     COUNT(cs.RECORD_ID) AS HOUR_COUNT
    FROM
     cbc_hours_list hs
    LEFT JOIN cbc_source_0002 cs ON HOUR (cs.create_time) = hs. HOUR
    AND cs.create_time > #{startTime}
    AND cs.create_time <= #{endTime}
    <#if sourceId?exists && sourceId !=''>
     AND SOURCE_ID = #{sourceId}
    
    GROUP BY
     hs. HOUR
    UNION ALL
    SELECT
     hs.HOUR AS HOUR,
     COUNT(cs.RECORD_ID) AS HOUR_COUNT
    FROM
     cbc_hours_list hs
    LEFT JOIN cbc_source_hs cs ON HOUR (cs.create_time) = hs. HOUR
    AND cs.create_time > #{startTime}
    AND cs.create_time <= #{endTime}
    <#if sourceId?exists && sourceId !=''>
     AND SOURCE_ID = #{sourceId}
    
    GROUP BY
     hs. HOUR
    UNION ALL
    SELECT
     hs.HOUR AS HOUR,
     COUNT(cs.RECORD_ID) AS HOUR_COUNT
    FROM
     cbc_hours_list hs
    LEFT JOIN cbc_source_kfyj cs ON HOUR (cs.create_time) = hs. HOUR
    AND cs.create_time > #{startTime}
    AND cs.create_time <= #{endTime}
    <#if sourceId?exists && sourceId !=''>
     AND SOURCE_ID = #{sourceId}
    
    GROUP BY
     hs. HOUR
    UNION ALL
    SELECT
     hs.HOUR AS HOUR,
     COUNT(cs.RECORD_ID) AS HOUR_COUNT
    FROM
     cbc_hours_list hs
    LEFT JOIN cbc_source_his_0002 cs ON HOUR (cs.create_time) = hs. HOUR
    AND cs.create_time > #{startTime}
    AND cs.create_time <= #{endTime}
    <#if sourceId?exists && sourceId !=''>
     AND SOURCE_ID = #{sourceId}
    
    GROUP BY
     hs. HOUR
    UNION ALL
    SELECT
     hs.HOUR AS HOUR,
     COUNT(cs.RECORD_ID) AS HOUR_COUNT
    FROM
     cbc_hours_list hs
    LEFT JOIN cbc_source_his_hs cs ON HOUR (cs.create_time) = hs. HOUR
    AND cs.create_time > #{startTime}
    AND cs.create_time <= #{endTime}
    <#if sourceId?exists && sourceId !=''>
     AND SOURCE_ID = #{sourceId}
    
    GROUP BY
     hs. HOUR
    UNION ALL
    SELECT
     hs.HOUR AS HOUR,
     COUNT(cs.RECORD_ID) AS HOUR_COUNT
    FROM
     cbc_hours_list hs
    LEFT JOIN cbc_source_his_kfyj cs ON HOUR (cs.create_time) = hs. HOUR
    AND cs.create_time > #{startTime}
    AND cs.create_time <= #{endTime}
    <#if sourceId?exists && sourceId !=''>
     AND SOURCE_ID = #{sourceId}
    
    GROUP BY
     hs. HOUR) t
   GROUP BY
    t.hour

效果

统计数为0的小时也可以查出来了。

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