複雜的SQL字符串解析

Question

我在SQL Server表下面的文本字段：（！）

1!1,3!0,23!0,288!0,340!0,521!0,24!0,38!0,26!0,27!0,281!0,19!0,470!0,568!0,601!0,2!1,251!0,7!2,140!0,285!0,11!2,33!0 

1. 想只檢索感嘆號之前的部分。所以對於1!1我只想要1，對於3!0我只想要3，對於23!0我只想要23。

2. 還想檢索感嘆號（！）後面的部分。所以對於1!1我只想要1，因爲3!0我只想0，對於23!0我只想要0。

點1和點2應插入到SQL Server表的不同列中。

Answer 1

我完全同意抱怨這類數據的人。然而，事實是，我們通常沒有任何對我們來源格式的控制。

這是我的方法...

首先你需要一個記號器。這個非常高效（可能是最快的非CLR）。在http://www.sqlservercentral.com/articles/Tally+Table/72993/

CREATE FUNCTION [dbo].[DelimitedSplit8K] 
--===== Define I/O parameters 
     (@pString VARCHAR(8000), @pDelimiter CHAR(1)) 
--WARNING!!! DO NOT USE MAX DATA-TYPES HERE! IT WILL KILL PERFORMANCE! 
RETURNS TABLE WITH SCHEMABINDING AS 
RETURN 
--===== "Inline" CTE Driven "Tally Table" produces values from 1 up to 10,000... 
    -- enough to cover VARCHAR(8000) 
    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 
; 
GO 

找到，那麼你消耗它是這樣的...

DECLARE @Wtf VARCHAR(1000) = '1!1,3!0,23!0,288!0,340!0,521!0,24!0,38!0,26!0,27!0,281!0,19!0,470!0,568!0,601!0,2!1,251!0,7!2,140!0,285!0,11!2,33!0' 

SELECT LEFT(Item, CHARINDEX('!', Item)-1) 
     ,RIGHT(Item, CHARINDEX('!', REVERSE(Item))-1) 
FROM [dbo].[DelimitedSplit8K](@Wtf, ',') 

功能發佈和解析邏輯可以集成到課程的單一功能。

Answer 2

我愛SQL Server的XML功能。這是解析數據的好方法。試試這個：

--Load the original string 
DECLARE @string nvarchar(max) = '1!2,3!4,5!6,7!8,9!10'; 

--Turn it into XML 
SET @string = REPLACE(@string,',','</SecondNumber></Pair><Pair><FirstNumber>') + '</SecondNumber></Pair>'; 
SET @string = '<Pair><FirstNumber>' + REPLACE(@string,'!','</FirstNumber><SecondNumber>'); 

--Show the new version of the string 
SELECT @string AS XmlIfiedString; 

--Load it into an XML variable 
DECLARE @xml XML = @string; 

--Now, First and Second Number from each pair... 
SELECT 
    Pairs.Pair.value('FirstNumber[1]','nvarchar(1024)') AS FirstNumber, 
    Pairs.Pair.value('SecondNumber[1]','nvarchar(1024)') AS SecondNumber 
FROM @xml.nodes('//*:Pair') Pairs(Pair); 

上述查詢變成了字符串轉換成XML這樣的：

<Pair><FirstNumber>1</FirstNumber><SecondNumber>2</SecondNumber></Pair> ... 

然後分析它返回像一個結果：

FirstNumber | SecondNumber 
----------- | ------------ 
      1 |   2 
      3 |   4 
      5 |   6 
      7 |   8 
      9 |   10 

Answer 3

我同意normaliz數據是最好的方法。但是，這裏是解析數據的XML解決方案

DECLARE @str VARCHAR(1000) = '1!1,3!0,23!0,288!0,340!0,521!0,24!0,38!0,26!0,27!0,281!0,19!0,470!0,568!0,601!0,2!1,251!0,7!2,140!0,285!0,11!2,33!0' 
    ,@xml XML 

SET @xml = CAST('<row><col>' + REPLACE(REPLACE(@str,'!','</col><col>'),',','</col></row><row><col>') + '</col></row>' AS XML) 

SELECT 
    line.col.value('col[1]', 'varchar(1000)') AS col1 
    ,line.col.value('col[2]', 'varchar(1000)') AS col2 
FROM @xml.nodes('/row') AS line(col)