Question

数据库表：

我有MySQL查询：

select  calendar.datefield AS date, 
      ( SELECT  IFNULL(SUM(visits),0)
            FROM  link_stats
            WHERE  link_stats.link_id = '1'
              AND  statDate = date
      ) AS visits, 
      ( SELECT  Round(IFNULL(SUM(leads * (rate/1000)),0),3)
            FROM  link_stats
            WHERE  link_stats.link_id = '1'
              AND  statDate = date
      ) AS cash, 
      ( SELECT  IFNULL(SUM(leads),0)
            FROM  link_stats
            WHERE  link_stats.link_id = '1'
              AND  statDate = date
      ) AS leads
    from  `calendar`
    where  `calendar`.`datefield` between '2016-05-10' AND '2016-05-11'

我尝试使用空白天生成每个链接的统计信息报告。

示例：

2016年1月11日至2016年1月20日期间，链接没有日期为12-01-2016的记录。

Answer 1

构建一个包含所有可能日期的表格。称之为TableOfDates并有一列：datefield

然后重新排列这样的查询：

select  d.datefield AS date,
        ls.visits, ls.cash, ls.leads
    from  TableOfDates d
    LEFT JOIN  `calendar` AS c  ON c.datefield = d.datefield
    LEFT JOIN  
      ( SELECT  statDate,
                IFNULL(SUM(visits),0) AS visits,
                Round(IFNULL(SUM(leads * (rate/1000)), 0),3) AS cash,
                IFNULL(SUM(leads),0) AS leads
            FROM  link_stats
            WHERE    ls.link_id = 1
              AND    statDate between '2016-01-11' AND '2016-01-20'
            GROUP BY statDate 
      ) AS ls  ON ls.statDate = d.datefield
    where  d.datefield        between '2016-01-11' AND '2016-01-20'

优化MySQL查询（生成统计信息）

1 个答案: