Mysql 创建临时表以显示查询中缺少的月份_Mysql_Sql_Left Join

Mysql 创建临时表以显示查询中缺少的月份

mysql sql

Mysql 创建临时表以显示查询中缺少的月份,mysql,sql,left-join,Mysql,Sql,Left Join,我正在尝试创建一个简单的MySQL查询，以获取一年中每个月的销售数据，按monthname和SalesName分组 CREATE TEMPORARY TABLE Cal (monthid INT, monthname VARCHAR(50)); INSERT INTO Cal (monthid, monthname) VALUES (1, 'January'), (2, 'February'), (3, 'March'), (4, 'April'), (5

我正在尝试创建一个简单的MySQL查询，以获取一年中每个月的销售数据，按

monthname

和

SalesName

分组

CREATE TEMPORARY TABLE Cal (monthid INT, monthname VARCHAR(50));
INSERT INTO Cal (monthid, monthname) VALUES
    (1, 'January'),
    (2, 'February'),
    (3, 'March'),
    (4, 'April'),
    (5, 'May'),
    (6, 'June'),
    (7, 'July'),
    (8, 'August'),
    (9, 'September'),
    (10, 'October'),
    (11, 'November'),
    (12, 'December');
CREATE TEMPORARY TABLE Sales AS SELECT SalesName FROM `Opportunity`;
SELECT concat(c.monthname, ' ', YEAR(CURDATE())) As `Period`,
s.SalesName,
IFNULL(CONVERT(AVG(o.GeneratedRevenue__c), SIGNED INTEGER), 0) As `AverageMonthlyRevenue`,
sum(CASE 
    WHEN c.monthid = Month(o.CloseDate)
    THEN o.Won
    ELSE 0
END) As `ClosedDeals`
FROM `Cal` c
join `Sales` s
left join `Opportunity` as o
on o.SalesName=s.SalesName and c.monthid=month(o.CloseDate)
GROUP By c.monthid, s.SalesName

对于

平均月平均值

，结果是正确的，但是对于

关闭的数据

，返回的结果完全没有意义

源数据库：

| Id | AccountName | SalesName | CloseDate | o.GeneratedRevenue__c | Won | Premium |
| -- | ------ | ------ | ------ | ------ | ------ | ------ |
|1|Mirazur|Grégoire|2020-05-19|1548|1|0
|2|Apicius|Edouard|2020-02-04|1344|1|1
|3|Arpège|Camille|2020-05-23|1456|1|1
|4|Les Apothicaires|Grégoire|2020-04-29|1635|1|0
|5|Le Bouillon|Camille|2020-12-10|1456|0|0
|6|Pink Mama|Edouard|2020-02-14|666|1|1

结果:

|Period | SalesName | AverageMonthlyRevenue| ClosedDeals |
| ------ | ------ | ------ |  ------ | 
|January 2020 | Camille     | 0     | 0 
|January 2020 | Edouard     | 0     | 0 
|January 2020 | Grégoire    | 0     | 0 
|February 2020 | Camille    | 0     | 0 
|February 2020 | Edouard    | 1005  | 4 
|February 2020 | Grégoire   | 0     | 0 
|March 2020 | Camille       | 0     | 0 
|March 2020 | Edouard       | 0     | 0 
|March 2020 | Grégoire      | 0     | 0 
|April 2020 | Camille       | 0     | 0 
|April 2020 | Edouard       | 0     | 0 
|April 2020 | Grégoire      | 1635  | 0 
|May 2020 | Camille         | 1456  | 2 
|May 2020 | Edouard         | 0     | 0 
|May 2020 | Grégoire        | 1548  | 0 
|June 2020 | Camille        | 0     | 0 
|June 2020 | Edouard        | 0     | 0 
|June 2020 | Grégoire       | 0     | 0 
|July 2020 | Camille        | 0     | 0 
|July 2020 | Edouard        | 0     | 0 
|July 2020 | Grégoire       | 0     | 0 
|August 2020 | Camille      | 0     | 0 
|August 2020 | Edouard      | 0     | 0 
|August 2020 | Grégoire     | 0     | 0 
|September 2020 | Camille   | 0     | 0

错误在您的销售临时表中。没有添加不同的记录，您只是在复制记录。您需要执行以下操作：

CREATE TEMPORARY TABLE Sales AS SELECT DISTINCT SalesName FROM `Opportunity`;

您不需要为此设置临时表。只需使用：

SELECT CONCAT(c.monthname, ' ', YEAR(CURDATE())) As Period,
s.SalesName,
       COALESCE(AVG(o.GeneratedRevenue__c), 0) As AverageMonthlyRevenue,
       COALESCE(SUM(o.won), 0) as ClosedDeals 
FROM Cal c CROSS JOIN
     (SELECT DISTINCT SalesName 
      FROM Opportunity s
     ) LEFT JOIN
     Opportunity o
     ON o.SalesName = s.SalesName AND
        c.monthid = MONTH(o.CloseDate)
GROUP BY c.monthid, s.SalesName;

注:

您的查询不考虑年份。这似乎很危险
您可以在临时表中使用
```
SELECT DISTINCT
```
，但不需要
```
sales
```
```
ClosedDetails
```
不需要
```
CASE
```
表达式
```
JOIN
```
应该始终有一个
```
ON
```
子句——即使MySQL允许这种非标准和混乱的语法。如果需要交叉连接，请使用
```
交叉连接
```

谢谢@Marshall，它确实解释了为什么除了平均数据之外所有数据都是重复的：）谢谢@Gordon Linoff，你的解释和详细信息对我帮助很大，我选择了Marshalls的答案，因为他是第一个解决问题的人，但非常感谢你的帮助@扬尼克赫尔穆特。没有临时表的解决方案是更好的解决方案，这就是我提供答案的原因。这还解决了“年”上缺少筛选的问题，并为关闭的数据提供了正确的代码。