Based on my experience, by creating a delimited expression from the employeeIDs, there is a tricky and nice solution for this problem. You should only create an string expression like ';123;434;365;' in-which 123, 434 and 365 are some employeeIDs. By calling the below procedure and passing this expression to it, you can fetch your desired records. Easily you can join the "another table" into this query. This solution is suitable in all versions of SQL server. Also, in comparison with using table variable or temp table, it is very faster and optimized solution.

CREATE PROCEDURE dbo.DoSomethingOnSomeEmployees  @List AS varchar(max)
AS
BEGIN
  SELECT EmployeeID 
  FROM EmployeesTable
  -- inner join AnotherTable on ...
  where @List like '%;'+cast(employeeID as varchar(20))+';%'
END
GO

Based on my experience, by creating a delimited expression from the employeeIDs, there is a tricky and nice solution for this problem. You should only create an string expression like ';123;434;365;' in-which 123, 434 and 365 are some employeeIDs. By calling the below procedure and passing this expression to it, you can fetch your desired records. Easily you can join the "another table" into this query. This solution is suitable in all versions of SQL server. Also, in comparison with using table variable or temp table, it is very faster and optimized solution.

CREATE PROCEDURE dbo.DoSomethingOnSomeEmployees  @List AS varchar(max)
AS
BEGIN
  SELECT EmployeeID 
  FROM EmployeesTable
  -- inner join AnotherTable on ...
  where @List like '%;'+cast(employeeID as varchar(20))+';%'
END
GO

SQL Server 2016(或更新版本)

您可以传入一个带分隔符的列表或JSON，并使用STRING_SPLIT()或OPENJSON()。

STRING_SPLIT ():

CREATE PROCEDURE dbo.DoSomethingWithEmployees
  @List varchar(max)
AS
BEGIN
  SET NOCOUNT ON;

  SELECT value FROM STRING_SPLIT(@List, ',');
END
GO
EXEC dbo.DoSomethingWithEmployees @List = '1,2,3';

OPENJSON ():

CREATE PROCEDURE dbo.DoSomethingWithEmployees
  @List varchar(max)
AS
BEGIN
  SET NOCOUNT ON;

  SELECT value FROM OPENJSON(CONCAT('["',
    REPLACE(STRING_ESCAPE(@List, 'JSON'), 
    ',', '","'), '"]')) AS j;
END
GO
EXEC dbo.DoSomethingWithEmployees @List = '1,2,3';

我在这里写了更多:

处理SQL Server中未知数量的参数 在SQL Server中使用OPENJSON进行有序字符串拆分

SQL Server 2008(或更新版本)

首先，在数据库中创建以下两个对象:

CREATE TYPE dbo.IDList
AS TABLE
(
  ID INT
);
GO

CREATE PROCEDURE dbo.DoSomethingWithEmployees
  @List AS dbo.IDList READONLY
AS
BEGIN
  SET NOCOUNT ON;
  
  SELECT ID FROM @List; 
END
GO

现在在你的c#代码中:

// Obtain your list of ids to send, this is just an example call to a helper utility function
int[] employeeIds = GetEmployeeIds();

DataTable tvp = new DataTable();
tvp.Columns.Add(new DataColumn("ID", typeof(int)));

// populate DataTable from your List here
foreach(var id in employeeIds)
    tvp.Rows.Add(id);

using (conn)
{
    SqlCommand cmd = new SqlCommand("dbo.DoSomethingWithEmployees", conn);
    cmd.CommandType = CommandType.StoredProcedure;
    SqlParameter tvparam = cmd.Parameters.AddWithValue("@List", tvp);
    // these next lines are important to map the C# DataTable object to the correct SQL User Defined Type
    tvparam.SqlDbType = SqlDbType.Structured;
    tvparam.TypeName = "dbo.IDList";
    // execute query, consume results, etc. here
}

SQL Server 2005

如果您使用的是SQL Server 2005，我仍然建议使用分割函数而不是XML。首先，创建一个函数:

CREATE FUNCTION dbo.SplitInts
(
   @List      VARCHAR(MAX),
   @Delimiter VARCHAR(255)
)
RETURNS TABLE
AS
  RETURN ( SELECT Item = CONVERT(INT, Item) FROM
      ( SELECT Item = x.i.value('(./text())[1]', 'varchar(max)')
        FROM ( SELECT [XML] = CONVERT(XML, '<i>'
        + REPLACE(@List, @Delimiter, '</i><i>') + '</i>').query('.')
          ) AS a CROSS APPLY [XML].nodes('i') AS x(i) ) AS y
      WHERE Item IS NOT NULL
  );
GO

现在你的存储过程可以是:

CREATE PROCEDURE dbo.DoSomethingWithEmployees
  @List VARCHAR(MAX)
AS
BEGIN
  SET NOCOUNT ON;
  
  SELECT EmployeeID = Item FROM dbo.SplitInts(@List, ','); 
END
GO

在你的c#代码中，你只需要将列表传递为'1,2,3,12'…

我发现传递表值参数的方法简化了使用该方法的解决方案的可维护性，并且与其他实现(包括XML和字符串分割)相比，常常提高了性能。

输入是明确定义的(没有人需要猜测分隔符是逗号还是分号)，并且我们对其他处理函数没有依赖关系，如果不检查存储过程的代码，这些依赖关系就不明显。

与使用用户定义的XML模式而不是udt的解决方案相比，这涉及到类似数量的步骤，但根据我的经验，管理、维护和阅读代码要简单得多。

在许多解决方案中，您可能只需要为许多存储过程重用一个或几个这样的udt(用户定义类型)。与本例一样，常见的要求是传递一个ID指针列表，函数名描述这些ID应该表示的上下文，类型名应该是泛型的。

CREATE TYPE dumyTable
AS TABLE
(
  RateCodeId int,
  RateLowerRange int,
  RateHigherRange int,
  RateRangeValue int
);
GO
CREATE PROCEDURE spInsertRateRanges
  @dt AS dumyTable READONLY
AS
BEGIN
  SET NOCOUNT ON;

  INSERT  tblRateCodeRange(RateCodeId,RateLowerRange,RateHigherRange,RateRangeValue) 
  SELECT * 
  FROM @dt 
END

从SQL Server 2016开始，您可以将列表作为NVARCHAR()并使用OPENJSON

DECLARE @EmployeeList nvarchar(500) = '[1,2,15]'


SELECT * 
FROM Employees
WHERE ID IN (SELECT VALUE FROM OPENJSON(@EmployeeList ))

上下文总是很重要的，比如数组的大小和复杂性。对于中小型榜单来说，这里列出的几个答案还不错，但有一些需要澄清的地方:

For splitting a delimited list, a SQLCLR-based splitter is the fastest. There are numerous examples around if you want to write your own, or you can just download the free SQL# library of CLR functions (which I wrote, but the String_Split function, and many others, are completely free). Splitting XML-based arrays can be fast, but you need to use attribute-based XML, not element-based XML (which is the only type shown in the answers here, though @AaronBertrand's XML example is the best as his code is using the text() XML function. For more info (i.e. performance analysis) on using XML to split lists, check out "Using XML to pass lists as parameters in SQL Server" by Phil Factor. Using TVPs is great (assuming you are using at least SQL Server 2008, or newer) as the data is streamed to the proc and shows up pre-parsed and strongly-typed as a table variable. HOWEVER, in most cases, storing all of the data in DataTable means duplicating the data in memory as it is copied from the original collection. Hence using the DataTable method of passing in TVPs does not work well for larger sets of data (i.e. does not scale well). XML, unlike simple delimited lists of Ints or Strings, can handle more than one-dimensional arrays, just like TVPs. But also just like the DataTable TVP method, XML does not scale well as it more than doubles the datasize in memory as it needs to additionally account for the overhead of the XML document.

说了这么多，如果你使用的数据很大，或者不是很大，但一直在增长，那么IEnumerable TVP方法是最好的选择，因为它将数据流传输到SQL Server(就像DataTable方法)，但不需要在内存中复制任何集合(不像任何其他方法)。我在这个回答中发布了一个SQL和c#代码的例子:

将字典传递给存储过程T-SQL