创建一个接受 id 列表的函数？

Question

我想创建一个这样的 SQL 函数（伪代码）：

function PeopleInCompanies(companyIds)
   SELECT * from Person WHERE CompanyId IN (companyIds)
end function

然后这样称呼它：

define companyIds = 1,2,3
select * from PeopleInCompanies(companyIds)

有可能吗？

Answer 1

您需要使用表格类型参数。假设CompanyID 是int：

CREATE TYPE dbo.ints AS TABLE ([value] int);
GO

CREATE FUNCTION dbo.PeopleInCompanies (@CompanyID dbo.ints READONLY)
RETURNS TABLE
AS RETURN

    SELECT P.* --This should be replaced by the columns you need.
    FROM dbo.Person P
         JOIN @CompanyID CI ON P.CompanyID = CI.[Value];

然后你会调用这个函数：

DECLARE @CompanyID dbo.ints;
INSERT INTO @CompanyID
VALUES (1),(2),(3);

SELECT *
FROM dbo.PeopleInCompanies(@CompanyID);

Answer 2

SQL Server 不支持宏替换。也就是说，您有 Gordon 和 Larnu 提到的表类型，或者您可以简单地解析/拆分分隔字符串

只是另一种选择

Declare @companyIds varchar(max) = '1,2,3'

Select A.*
  From Person A
  Join string_split(@companyIds,',') B 
    on A.CompanyID = B.Value