如何将逗号分隔的变量值转换为 SQL Server 2012 中的行？

Question

I have a variable in my stored procedure `@param varchar', the parameter value will be like '333,445,443,222' or '555'

I need to store into as row in the #Employee table, Code column.

Expected output:

#Employee temp table:

Code
----
333
445
443
222

Answer 1

It will work with any SQL server version. User define table function

CREATE FUNCTION dbo.SplitString
(
  @Value     nvarchar(max),
  @Delim    nvarchar(5)
)
RETURNS TABLE
AS
  RETURN ( SELECT [Value] FROM 
  ( 
    SELECT [Value] = LTRIM(RTRIM(SUBSTRING(@Value, [Number],
      CHARINDEX(@Delim, @Value + @Delim, [Number]) - [Number])))
    FROM (SELECT Number = ROW_NUMBER() OVER (ORDER BY name)
      FROM sys.all_columns) AS x WHERE Number <= LEN(@Value)
      AND SUBSTRING(@Delim + @Value, [Number], DATALENGTH(@Delim)/2) = @Delim
    ) AS y
  );

and then it can be used

DECLARE @param varchar(1000)
SET @param = '333,445,443,222'

SELECT value AS Code FROM dbo.SplitString(@param, ',');

Demo: http://sqlfiddle.com/#!18/9eecb/89486

Answer 2

Since SQL Server 2016, there has been a built-in function to do this:

select s.value
from string_split(@param, ',') s

I would recommend using it. The one downside to string_split() is that it does not provide ordering in the string. If ordering is important and there are no duplicates, then charindex() can be used. If there can be duplicates, then I recommend a recursive CTE.

Answer 3

Your problem can be solved with recursive CTE (need to know about maxrecursion ):

create function my_split(@s nvarchar(max), @d nvarchar(1))
  returns table return
    with
      r as (
        select
          iif(p > 0, left(@s, p - 1), @s) as s,
          iif(p > 0, right(@s, len(@s) - p), '') as r
        from (select charindex(@d, @s)) as a(p)
        union all
        select
          iif(p > 0, left(r, p - 1), r),
          iif(p > 0, right(r, len(r) - p), '')
        from r
        cross apply (select charindex(@d, r)) as a(p)
        where r != ''
      )
    select s from r;

Output:

+----+-----------------+------+
|    |      param      | code |
+----+-----------------+------+
|  1 | 333,445,443,222 |  333 |
|  2 | 333,445,443,222 |  445 |
|  3 | 333,445,443,222 |  443 |
|  4 | 333,445,443,222 |  222 |
|  5 | 555             |  555 |
+----+-----------------+------+

Demo .