Question

我的表格结构如下：

id  |sourceid |item |freq |siteid |customerid
61  |226      |2    |1    |262    |1  
301 |226      |1    |1    |262    |1  
495 |1        |32   |1    |262    |1  
658 |166      |8    |16   |262    |1  
1   |2        |4    |1    |333    |2

我正在尝试根据“ freq”的值将“ item”的总和加在一起，并按“ customerid”和“ siteid”分组

因此，在上面的网站1中，客户1的站点262的总频率为35（2 + 1 + 32）我需要对其他频率执行相同操作我有下面的

CREATE 
    ALGORITHM = UNDEFINED 
    DEFINER = `root`@`localhost` 
    SQL SECURITY DEFINER
VIEW `new_view` AS
    SELECT 
        `siteitems`.`customerID` AS `CID`,
        `siteitems`.`siteID` AS `AID`,
        SUM(`siteitems`.`item`) AS `Semi-annual`
    FROM
        `contractitems` `siteitems`
    WHERE
        (`siteitems`.`freq` = 1)
    GROUP BY `siteitems`.`customerID` , `siteitems`.`siteID`

哪一位给我1的频率我不确定如何在同一表格中添加频率为2等的另一列。

我应该删除WHERE子句并更改SUM（以某种方式）以仅对正确的频率求和，还是我需要再次加入表？

Answer 1

根据您的描述，这应该可以满足您的要求：

select customerid, siteid, freq, sum(item)
from contractitems ci
group by customerid, siteid, freq
order by customerid, siteid, freq;

但是，您可能还需要条件聚合：

select customerid, siteid,
       sum(case when freq = 1 then item else 0 end) as item_1,
       sum(case when freq = 2 then item else 0 end) as item_2,
       sum(case when freq = 4 then item else 0 end) as item_4,
       sum(case when freq = 8 then item else 0 end) as item_8,
       sum(case when freq = 16 then item else 0 end) as item_16
from contractitems ci
group by customerid, siteid
order by customerid, siteid;

一个表上有多个条件和列

1 个答案: