sql server - values - 將逗號分隔的字符串轉換為單獨的行




t sql split column values (8)

我有一個像這樣的SQL表:

| SomeID         | OtherID     | Data
+----------------+-------------+-------------------
| abcdef-.....   | cdef123-... | 18,20,22
| abcdef-.....   | 4554a24-... | 17,19
| 987654-.....   | 12324a2-... | 13,19,20

有沒有一個查詢,我可以執行查詢,如SELECT OtherID, SplitData WHERE SomeID = 'abcdef-.......' ,它返回單個行,如下所示:

| OtherID     | SplitData
+-------------+-------------------
| cdef123-... | 18
| cdef123-... | 20
| cdef123-... | 22
| 4554a24-... | 17
| 4554a24-... | 19

基本上我的數據在逗號分割成單行?

我知道將comma-separated字符串存儲到關係數據庫中聽起來很愚蠢,但消費者應用程序中的正常使用情況會非常有用。

我不想在應用程序中進行拆分,因為我需要分頁,所以我想在重構整個應用程序之前探索選項。

它是SQL Server 2008 (非R2)。


當使用這種方法時,您必須確保您的值中沒有包含任何非法的XML - user1151923

我總是使用XML方法。 確保你使用VALID XML。 我有兩個函數可以在有效的XML和文本之間進行轉換。 (我傾向於去掉回車,因為我通常不需要它們。

CREATE FUNCTION dbo.udf_ConvertTextToXML (@Text varchar(MAX)) 
    RETURNS varchar(MAX)
AS
    BEGIN
        SET @Text = REPLACE(@Text,CHAR(10),'')
        SET @Text = REPLACE(@Text,CHAR(13),'')
        SET @Text = REPLACE(@Text,'<','&lt;')
        SET @Text = REPLACE(@Text,'&','&amp;')
        SET @Text = REPLACE(@Text,'>','&gt;')
        SET @Text = REPLACE(@Text,'''','&apos;')
        SET @Text = REPLACE(@Text,'"','&quot;')
    RETURN @Text
END


CREATE FUNCTION dbo.udf_ConvertTextFromXML (@Text VARCHAR(MAX)) 
    RETURNS VARCHAR(max)
AS
    BEGIN
        SET @Text = REPLACE(@Text,'&lt;','<')
        SET @Text = REPLACE(@Text,'&amp;','&')
        SET @Text = REPLACE(@Text,'&gt;','>')
        SET @Text = REPLACE(@Text,'&apos;','''')
        SET @Text = REPLACE(@Text,'&quot;','"')
    RETURN @Text
END

下面的工作在SQL Server 2008上

select *, ROW_NUMBER() OVER(order by items) as row# 
from 
( select 134 myColumn1, 34 myColumn2, 'd,c,k,e,f,g,h,a' comaSeperatedColumn) myTable
    cross apply 
SPLIT (rtrim(comaSeperatedColumn), ',') splitedTable -- gives 'items'  column 

將所有笛卡兒產品與原始表列一起加上拆分錶的“項目”。


很高興看到它已在2016年版本中得到解決,但對於那些不在這一方面的人士,這裡有兩種通用和簡化版本的方法。

XML方法更短,但是當然需要字符串來允許xml技巧(沒有'壞'字符)。

XML的方法:

create function dbo.splitString(@input Varchar(max), @Splitter VarChar(99)) returns table as
Return
    SELECT Split.a.value('.', 'VARCHAR(max)') AS Data FROM
    ( SELECT CAST ('<M>' + REPLACE(@input, @Splitter, '</M><M>') + '</M>' AS XML) AS Data 
    ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a); 

遞歸方法:

create function dbo.splitString(@input Varchar(max), @Splitter Varchar(99)) returns table as
Return
  with tmp (DataItem, ix) as
   ( select @input  , CHARINDEX('',@Input)  --Recu. start, ignored val to get the types right
     union all
     select Substring(@input, ix+1,ix2-ix-1), ix2
     from (Select *, CHARINDEX(@Splitter,@[email protected],ix+1) ix2 from tmp) x where ix2<>0
   ) select DataItem from tmp where ix<>0

行動中的功能

Create table TEST_X (A int, CSV Varchar(100));
Insert into test_x select 1, 'A,B';
Insert into test_x select 2, 'C,D';

Select A,data from TEST_X x cross apply dbo.splitString(x.CSV,',') Y;

Drop table TEST_X

XML-METHOD 2:Unicode友好😀 (除了提供Max Hodges) create function dbo.splitString(@input nVarchar(max), @Splitter nVarchar(99)) returns table as Return SELECT Split.a.value('.', 'NVARCHAR(max)') AS Data FROM ( SELECT CAST ('<M>' + REPLACE(@input, @Splitter, '</M><M>') + '</M>' AS XML) AS Data ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a);


您可以使用SQL Server的精彩遞歸函數:

樣品表:

CREATE TABLE Testdata
(
    SomeID INT,
    OtherID INT,
    String VARCHAR(MAX)
)

INSERT Testdata SELECT 1,  9, '18,20,22'
INSERT Testdata SELECT 2,  8, '17,19'
INSERT Testdata SELECT 3,  7, '13,19,20'
INSERT Testdata SELECT 4,  6, ''
INSERT Testdata SELECT 9, 11, '1,2,3,4'

查詢

;WITH tmp(SomeID, OtherID, DataItem, String) AS
(
    SELECT
        SomeID,
        OtherID,
        LEFT(String, CHARINDEX(',', String + ',') - 1),
        STUFF(String, 1, CHARINDEX(',', String + ','), '')
    FROM Testdata
    UNION all

    SELECT
        SomeID,
        OtherID,
        LEFT(String, CHARINDEX(',', String + ',') - 1),
        STUFF(String, 1, CHARINDEX(',', String + ','), '')
    FROM tmp
    WHERE
        String > ''
)

SELECT
    SomeID,
    OtherID,
    DataItem
FROM tmp
ORDER BY SomeID
-- OPTION (maxrecursion 0)
-- normally recursion is limited to 100. If you know you have very long
-- strings, uncomment the option

產量

 SomeID | OtherID | DataItem 
--------+---------+----------
 1      | 9       | 18       
 1      | 9       | 20       
 1      | 9       | 22       
 2      | 8       | 17       
 2      | 8       | 19       
 3      | 7       | 13       
 3      | 7       | 19       
 3      | 7       | 20       
 4      | 6       |          
 9      | 11      | 1        
 9      | 11      | 2        
 9      | 11      | 3        
 9      | 11      | 4        

最後, SQL Server 2016的等待已經結束。 他們引入了分割字符串函數STRING_SPLIT

select OtherID, cs.Value --SplitData
from yourtable
cross apply STRING_SPLIT (Data, ',') cs

所有其他將字符串拆分為XML,Tally表,while循環等的方法都被這個STRING_SPLIT函數吹走了。

這是一篇很好的文章,其性能比較: 性能驚喜和假設:STRING_SPLIT

對於舊版本,這裡使用計數表是一個拆分字符串函數(最好的方法)

CREATE FUNCTION [dbo].[DelimitedSplit8K]
        (@pString VARCHAR(8000), @pDelimiter CHAR(1))
RETURNS TABLE WITH SCHEMABINDING AS
 RETURN
--===== "Inline" CTE Driven "Tally Table" produces values from 0 up to 10,000...
     -- enough to cover NVARCHAR(4000)
  WITH E1(N) AS (
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
                 SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
                ),                          --10E+1 or 10 rows
       E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows
       E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max
 cteTally(N) AS (--==== This provides the "base" CTE and limits the number of rows right up front
                     -- for both a performance gain and prevention of accidental "overruns"
                 SELECT TOP (ISNULL(DATALENGTH(@pString),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
                ),
cteStart(N1) AS (--==== This returns N+1 (starting position of each "element" just once for each delimiter)
                 SELECT 1 UNION ALL
                 SELECT t.N+1 FROM cteTally t WHERE SUBSTRING(@pString,t.N,1) = @pDelimiter
                ),
cteLen(N1,L1) AS(--==== Return start and length (for use in substring)
                 SELECT s.N1,
                        ISNULL(NULLIF(CHARINDEX(@pDelimiter,@pString,s.N1),0)-s.N1,8000)
                   FROM cteStart s
                )
--===== Do the actual split. The ISNULL/NULLIF combo handles the length for the final element when no delimiter is found.
 SELECT ItemNumber = ROW_NUMBER() OVER(ORDER BY l.N1),
        Item       = SUBSTRING(@pString, l.N1, l.L1)
   FROM cteLen l
;

來自Tally OH! 改進的SQL 8K“CSV分割器”功能


檢查這個

 SELECT A.OtherID,  
     Split.a.value('.', 'VARCHAR(100)') AS Data  
 FROM  
 (
     SELECT OtherID,  
         CAST ('<M>' + REPLACE(Data, ',', '</M><M>') + '</M>' AS XML) AS Data  
     FROM  Table1
 ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a); 

DECLARE @id_list VARCHAR(MAX) = '1234,23,56,576,1231,567,122,87876,57553,1216'
DECLARE @table TABLE ( id VARCHAR(50) )
DECLARE @x INT = 0
DECLARE @firstcomma INT = 0
DECLARE @nextcomma INT = 0

SET @x = LEN(@id_list) - LEN(REPLACE(@id_list, ',', '')) + 1 -- number of ids in id_list

WHILE @x > 0
    BEGIN
        SET @nextcomma = CASE WHEN CHARINDEX(',', @id_list, @firstcomma + 1) = 0
                              THEN LEN(@id_list) + 1
                              ELSE CHARINDEX(',', @id_list, @firstcomma + 1)
                         END
        INSERT  INTO @table
        VALUES  ( SUBSTRING(@id_list, @firstcomma + 1, (@nextcomma - @firstcomma) - 1) )
        SET @firstcomma = CHARINDEX(',', @id_list, @firstcomma + 1)
        SET @x = @x - 1
    END

SELECT  *
FROM    @table

select t.OtherID,x.Kod
    from testData t
    cross apply (select Code from dbo.Split(t.Data,',') ) x




comma