将一行加入所有行并返回所有行

问题描述：

我可以从我的表

| id_outlet| date       |  count(msisdn) |  
| 34.10.1  |  2014-08   |      0         |
| 34.10.1  |  2014-09   |      3         |
| 34.10.1  |  2014-10   |      2         |
| 34.10.2  |  2014-08   |      1         |
| 34.10.2  |  2014-09   |      0         |
| 34.10.2  |  2014-10   |      0         |

所以我有2张桌子
1.桌子出风口(独特)
2.表销售(表出口的详细信息)
如您在我的第二张表中所见，有3个周期(2014-08、2014-09、2014-10)
我想像这样的示例在第一个表中将其与id_outlet连接起来.
我可以吗?
请帮助我

So I have 2 tables
1. table outlet (unique)
2. table sales (detail of table outlet)
As u see in my second table there are 3 periode (2014-08, 2014-09, 2014-10)
I want join that periode with id_outlet in first table like that example.
Can I?
Please Help me

答

使用交叉联接:-

SELECT
    o.id_outlet,
    s_main.periode,
    o.branch, 
    count(msisdn)
FROM
(
    SELECT DISTINCT SUBSTRING(date,1,7) AS periode
    FROM sales
) s_main 
CROSS JOIN outlet o
LEFT OUTER JOIN sales s
ON s_main.periode = SUBSTRING(s.date,1,7)
AND o.id_outlet = s.id_outlet
WHERE (o.STATUS LIKE 'STREET%')
GROUP BY s_main.periode, o.branch, o.id_outlet

如果您有日期表，则可以使用该表而不是子查询来获取日期(这还避免了潜在的问题，即当月的销售量为零时，结果中没有日期任何出口).

If you have a table of dates then you can just use that rather than the sub query to get the dates (which also avoids the potential problem of not having a date in the results for a month where there has been zero sales for any outlet).

将一行加入所有行并返回所有行

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