Sql 我一排只想要一个国家？

我一排只想要一个国家

我加入了两列

SELECT  
    brief_title AS Title,
    study_type  AS [Study Type],
    location_countries_country + location_facility_address_country AS Country,
FROM 
    [dbo].[ClinicalTrialStaging] 
WHERE
    study_type = 'all' 
    AND (location_countries_country LIKE '%United States%' OR 
         location_facility_address_country LIKE '%United States%')

我得到了这个结果：

Country
----------------------------
United States|United States|
United States|United States|
United States|United States|

---

同一排我有两个国家，但我只希望某一排有一个国家

我想你要找的是

    GROUP BY country

例如：

    location_countries_country + location_facility_address_country AS Country 
    from customer         
    WHERE (location_countries_country like '%United States%' or 
    location_facility_address_country like '%United States%')
    GROUP BY Country

---

编辑您的帖子将代码放在一个片段上更容易阅读=/另外，请详细说明一下表格。实际上在大多数SQL方言中，

GROUP BY

必须在

WHERE

子句之后…我的错，只是忘了将其更改为HAVING，但HAVING应仅应用于聚合列-例如，如果使用

SUM

或

COUNT

-则不适用于“正常”条件，如

之类的
。。。。。