计算列中的城市数量 - SQL 服务器

Question

我有一列包含与每个客户关联的客户标签（以逗号分隔）。

我需要在 ClientLabels 列中找到状态多于或少于 1 个的客户。换句话说，找到需要添加 State（当根本没有指定 State 时）或删除（当指定额外 State 时，通常发生在 Client 移出 State 或 Employees Error 时）的异常。

我们可以服务的所有州：加利福尼亚州、亚利桑那州、德克萨斯州、弗吉尼亚州和华盛顿州。

P.S。如果客户要搬到不在上述列表中的任何州，它将立即变为非活动状态，因此阿拉斯加（例如）不可能出现在 ClientLabels 列中。

CREATE TABLE Clients
(ClientId INT, ClientName VARCHAR(100), ClientLabels VARCHAR(max));

INSERT INTO Clients
VALUES
(1 , 'Justin Bieber', 'California, Musician, Male'),
(2 , 'Lionel Messi', 'Washington, Soccer Player, Male'),
(3 , 'Nicolas Cage', 'California, Actor, Male'),
(4 , 'Harry Potter', 'Fake, Male'),
(5 , 'Tom Holland', 'Arizona, Actor, California, Male'),
(6 , 'Ariana Grande', 'Texas, Musician, Female'),
(7 , 'Madonna', 'Virginia, Musician, Female'),
(8 , 'Dwayne Johnson', 'California, Actor, Male')


SELECT * FROM Clients

我需要的输出：

ClientId	ClientName	ClientLabels	NumberOfStates
1	Justin Bieber	California, Musician, Male	1
2	Lionel Messi	Washington, Soccer Player, Male	1
3	Nicolas Cage	California, Actor, Male	1
4	Harry Potter	Fake, Male	0
5	Tom Holland	Arizona, Actor, California, Male	2
6	Ariana Grande	Texas, Musician, Female	1
7	Madonna	Virginia, Musician, Female	1
8	Dwayne Johnson	California, Actor, Male	1

我已经开始编写代码，但不知道如何完成：

SELECT c.*,
        COUNT(c.ClientLabels) OVER(PARTITION BY c.ClientId) AS NumberOfStates

FROM Clients AS c

Answer 1

如果你 sql 服务器版本支持 STRING_SPLIT 功能你可以尝试使用 STRING_SPLIT with CROSS APPLY split ClientLabels by commna each ClientId.

然后使用条件聚合函数统计NumberOfStates

SELECT ClientId,
       ClientName,
       ClientLabels,
       COUNT(CASE WHEN trim(v.value) IN ('California','Arizona', 'Texas', 'Virginia', 'Washington') THEN 1 END) NumberOfStates
FROM Clients c
CROSS APPLY STRING_SPLIT(c.ClientLabels,',') v
GROUP BY ClientId,ClientName,ClientLabels

sqlfiddle

Answer 2

您可以试试下面的查询。

declare @Clients table(ClientId INT, ClientName VARCHAR(100), ClientLabels VARCHAR(max))
declare @labels table(label varchar(100))

insert into @Clients
VALUES
(1 , 'Justin Bieber', 'California, Musician, Male'),
(2 , 'Lionel Messi', 'Washington, Soccer Player, Male'),
(3 , 'Tom Holland', 'Arizona, Actor, California, Male'),
(4 , 'Harry Potter', 'Fake, Male')

insert into @labels
values('California')
,('Arizona')
,('Texas')
,('Virginia')
,('Washington')

select distinct c.*,case when cl.label is null then 0 
else count(*)over(partition by clientid order by clientid) end as [NumberOfStates]  
from @Clients c
left join @labels cl
on c.ClientLabels like '%' + cl.label + '%'

计算列中的城市数量 - SQL 服务器

Count the Number of Cities in the column - SQL Server

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