從T-SQL分隔字符串解析整數值的更好方法

Question

我有一個SQLServer2008 R2存儲過程，它包含從分隔字符串中解析出整數的算法。

這裏的SQL代碼，我通過了分隔字符串循環，並提取可能的分隔字符串中存在的任何號碼做出的一個例子：

-- Create a delimited list for testing 
DECLARE @NumericList nvarchar(MAX) = N'1, 33,44 ,55, foo ,666,77 77,8,bar,9,10' 

-- Declare the delimiter 
DECLARE @ListDelimiter VARCHAR(1) = ',' 

-- Remove white space from the list 
SET @NumericList = REPLACE(@NumericList, ' ',''); 

-- Var that will hold the value of the delimited item during the while-loop 
DECLARE @NumberInScope VARCHAR(MAX) 

WHILE(LEN(@NumericList) > 0) 
BEGIN 
    -- Get the value to the left of the first delimiter. 
    IF(CHARINDEX(@ListDelimiter, @NumericList) > 0) 
     SET @NumberInScope = LEFT(@NumericList, CHARINDEX(@ListDelimiter, @NumericList)) 
    ELSE 
     SET @NumberInScope = @NumericList 

    -- Remove the @NumberInScope value from the @NumericList 
    SET @NumericList = RIGHT(@NumericList, LEN(@NumericList) - LEN(@NumberInScope)) 

    -- Remove the delimiter from the @NumberInScope 
    SET @NumberInScope = REPLACE(@NumberInScope,@ListDelimiter,'') 

    -- Print only the integer values 
    IF(ISNUMERIC(@NumberInScope) = 1) 
    BEGIN 
     PRINT @NumberInScope 
    END 
END 

上面的代碼工作正常，但檢查代碼後在我看來，做同樣的事情必須有一種更簡潔的方式。換句話說，是否有任何字符串函數（或者任何新的R2函數，可能），我忽略了我可以實現的那樣會縮小代碼，並且希望更容易閱讀？

Answer 1

下面是代碼，您也可以創建一個「分裂」的功能和使用

DECLARE @NumericList nvarchar(max) = N'1, 33,44 ,55, foo ,666,77 77,8,bar,9,10' 

;WITH cte as (
SELECT CAST(1 as bigint) p1, CHARINDEX(',', @NumericList+',') p2, 
CAST(null as Nvarchar(max)) NumberInScope 
UNION ALL 
SELECT p2 + 1, CHARINDEX(',',@NumericList+',', p2 + 1), 
SUBSTRING(@NumericList, p1, p2-p1) 
FROM cte WHERE p2>0 
) 
SELECT NumberInScope from cte WHERE isnumeric(NumberInScope) > 0 
OPTION (MAXRECURSION 0) 

Answer 2

的明確的文章是顯示一個分裂的CSV "Arrays and Lists in SQL Server 2005 and Beyond"

以下幾種方法：CLR，數字表，WHILE循環

Answer 3

從MSSql Server 2016開始，有一個新的關鍵字STRING_SPLIT引入了所需的操作。

SELECT STRING_SPLIT (string , separator) 

參考https://msdn.microsoft.com/en-us/library/mt684588.aspx