解析查詢中的SQL字段

Question

我已經繼承了一個用戶個人信息數據庫，其中包含一個用於個人興趣的列。多個興趣由管道（|）分隔。在一個SQL查詢，我怎麼可以拆分場與該值：2 | 27 | 33 | 14 | 15

看起來像這樣：

2 
27 
33 
14 
15 

Answer 1

確切語法取決於其dbms您使用。假設你正在使用MSSQL這是一般語法

STRING_SPLIT (string , separator) 

例如

DECLARE @string_to_be_split NVARCHAR(400) = '2|27|33|14|15' 

SELECT value 
FROM STRING_SPLIT(@string_to_be_split, '|') 
WHERE RTRIM(value) <> ''; 

Answer 2

編輯 - 可以發誓，我看到的SQL Server

如果不是2016年，幾乎任何分割/解析函數都可以。

選項1 - 以UDF

Declare @YourTable table (ID int,Interests varchar(250)) 
Insert Into @YourTable values 
(1,'2|27|33|14|15') 

Select A.ID 
     ,B.* 
From @YourTable A 
Cross Apply [dbo].[udf-Str-Parse](A.Interests,'|') B 

選項2 - 如果沒有一個UDF

Select A.ID 
     ,B.* 
From @YourTable A 
Cross Apply (
       Select RetSeq = Row_Number() over (Order By (Select null)) 
         ,RetVal = LTrim(RTrim(B.i.value('(./text())[1]', 'varchar(max)'))) 
       From (Select x = Cast('<x>' + replace((Select replace(A.Interests,'|','§§Split§§') as [*] For XML Path('')),'§§Split§§','</x><x>')+'</x>' as xml).query('.')) as X 
       Cross Apply x.nodes('x') AS B(i) 
      ) B 

都返回

ID RetSeq RetVal 
1 1  2 
1 2  27 
1 3  33 
1 4  14 
1 5  15 

的UDF如果有興趣

CREATE FUNCTION [dbo].[udf-Str-Parse] (@String varchar(max),@Delimiter varchar(10)) 
Returns Table 
As 
Return ( 
    Select RetSeq = Row_Number() over (Order By (Select null)) 
      ,RetVal = LTrim(RTrim(B.i.value('(./text())[1]', 'varchar(max)'))) 
    From (Select x = Cast('<x>' + replace((Select replace(@String,@Delimiter,'§§Split§§') as [*] For XML Path('')),'§§Split§§','</x><x>')+'</x>' as xml).query('.')) as X 
    Cross Apply x.nodes('x') AS B(i) 
); 
--Thanks Shnugo for making this XML safe 
--Select * from [dbo].[udf-Str-Parse]('Dog,Cat,House,Car',',') 
--Select * from [dbo].[udf-Str-Parse]('John Cappelletti was here',' ') 
--Select * from [dbo].[udf-Str-Parse]('this,is,<test>,for,< & >',',')