Question

我应该根据我的要求组合两个结果字段。例如，下面的查询提供了如图所示的结果。但我需要一个案例陈述，声明'wind'和'wind c'都是相同的，因此将其总和结合起来。

SELECT result, COUNT(*) AS total from(
SELECT t.Id AS Id,
  CASE 
   WHEN LTRIM(RTRIM(AC)) = ' ' THEN AG 
   WHEN LOWER(AC) IS NOT NULL THEN LOWER(AC) 
   ELSE LOWER(AG) 
  END AS result,MaxDate,
FROM [DC_20160601] t
INNER JOIN ( SELECT Id, MAX(DateTime) AS MaxDate
FROM [DC_20160601]
GROUP BY Id) tm
ON t.Id = tm.Id AND t.DateTime = tm.MaxDate)
GROUP BY result

当前结果：

Result    Total
Wind      1212
Wind c    345
sqrim     321
sqrim mob 123

预期结果：

Result      Total
Wind mobile  1557
Sqrim mobile 444

Answer 1

您可以通过substring_index

选择字符串中的第一个单词

SELECT SUBSTRING_INDEX(`result`, ' ', 1);

现在按result

的第一个单词分组

SELECT SUBSTRING_INDEX(`result`, ' ', 1), COUNT(*) AS total from(
SELECT t.Id AS Id,
  CASE 
   WHEN LTRIM(RTRIM(AC)) = ' ' THEN AG 
   WHEN LOWER(AC) IS NOT NULL THEN LOWER(AC) 
   ELSE LOWER(AG) 
  END AS result,MaxDate,
FROM [DC_20160601] t
INNER JOIN ( SELECT Id, MAX(DateTime) AS MaxDate
FROM [DC_20160601]
GROUP BY Id) tm
ON t.Id = tm.Id AND t.DateTime = tm.MaxDate)
GROUP BY SUBSTRING_INDEX(`result`, ' ', 1)

Answer 2

您可能会尝试在第一个空格之前提取所有内容并将其用于分组：

SUBSTRING_INDEX(result, ' ', 1)

否则，您需要维护一个查找表，以便将多个变体与单个结果匹配。

Answer 3

您可以将case语句添加为外部查询。假设您的查询返回您发布的当前结果，以下是所需案例语句的示例： select case when a.result = 'Wind' or a.result = 'Wind c' then 'Wind mobile' else case when a.result = 'sqrim' or a.result = 'sqrim mob' then 'Squirm mobile' end end as res, sum(total) from ( SELECT result, COUNT(*) AS total from( SELECT t.Id AS Id, CASE WHEN LTRIM(RTRIM(AC)) = ' ' THEN AG WHEN LOWER(AC) IS NOT NULL THEN LOWER(AC) ELSE LOWER(AG) END AS result,MaxDate, FROM [DC_20160601] t INNER JOIN ( SELECT Id, MAX(DateTime) AS MaxDate FROM [DC_20160601] GROUP BY Id) tm ON t.Id = tm.Id AND t.DateTime = tm.MaxDate) GROUP BY result ) a group by res 最好在查找表中指定case语句中的值并从那里获取它们，或者如果需要，你可以添加其他的作为case语句，但它不理想...... 希望这有帮助！

SQL查询结合两个字段的总和

3 个答案: