我可以在SQL中删除案例中的非字母数字字符吗？

Question

由于我无法创建任何函数或过程，因此在编写SQL查询时遇到问题。这是我当前的查询

SELECT      ProductData.Customer_ID, ProductData.Product_Type
                CASE
                    WHEN ProductData.Product_Title = 'A_Title' THEN 'A_Title' ELSE 'R_Title' END AS R_Title
                CASE
                    WHEN ProductData.Product_Title = 'A_Title' AND ProductData.Product_Category != 'A_Category' THEN **(REMOVE Non-alphanumeric Character)**
                    WHEN ProductData.Product_Category = 'A_Category' THEN 'A_Category' ELSE 'R_Category' END AS R_Category,
FROM        ProductData

我希望能够使用以下代码作为上面的（删除非字母数字字符）中第二个CASE WHEN的第一行的结果，但仍然没有找到使其工作的方法。

while @@rowcount > 0
        update  ProductData
        set     Product_Category = replace(Product_Category, substring(Product_Category, patindex('%[^a-zA-Z ]%', Product_Category), 1), '')

建议非常感谢。

Answer 1

从Alan Burstein那里得到了很好的功能，称为PatExclude8K，我将其包括在内

CREATE FUNCTION dbo.PatExclude8K
(
    @String VARCHAR(8000),
    @Pattern VARCHAR(50)
) 
/*******************************************************************************
 Purpose:
 Given a string (@String) and a pattern (@Pattern) of characters to remove, 
 remove the patterned characters from the string.

Usage:
--===== Basic Syntax Example
 SELECT CleanedString 
 FROM dbo.PatExclude8K(@String,@Pattern);

--===== Remove all but Alpha characters
 SELECT CleanedString 
 FROM dbo.SomeTable st
 CROSS APPLY dbo.PatExclude8K(st.SomeString,'%[^A-Za-z]%');

--===== Remove all but Numeric digits
 SELECT CleanedString
 FROM dbo.SomeTable st
 CROSS APPLY dbo.PatExclude8K(st.SomeString,'%[^0-9]%');

 Programmer Notes:
 1. @Pattern is not case sensitive (the function can be easily modified to make it so)
 2. There is no need to include the "%" before and/or after your pattern since since we 
    are evaluating each character individually

 Revision History:
 Rev 00 - 10/27/2014 Initial Development - Alan Burstein

 Rev 01 - 10/29/2014 Mar 2007 - Alan Burstein
        - Redesigned based on the dbo.STRIP_NUM_EE by Eirikur Eiriksson
          (see: http://www.sqlservercentral.com/Forums/Topic1585850-391-2.aspx)
        - change how the cte tally table is created 
        - put the include/exclude logic in a CASE statement instead of a WHERE clause
        - Added Latin1_General_BIN Colation
        - Add code to use the pattern as a parameter.

 Rev 02 - 11/6/2014
        - Added final performane enhancement (more cudo's to Eirikur Eiriksson)
        - Put 0 = PATINDEX filter logic into the WHERE clause

Rev 03 - 5/16/2015
        - Updated code to deal with special XML characters
*******************************************************************************/
RETURNS TABLE WITH SCHEMABINDING AS
RETURN
WITH
E1(N) AS (SELECT N FROM (VALUES (NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL)) AS X(N)),
itally(N) AS 
(
  SELECT TOP(CONVERT(INT,LEN(@String),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
  FROM E1 T1 CROSS JOIN E1 T2 CROSS JOIN E1 T3 CROSS JOIN E1 T4
) 
SELECT NewString =
((
  SELECT SUBSTRING(@String,N,1)
  FROM iTally
  WHERE 0 = PATINDEX(@Pattern,SUBSTRING(@String COLLATE Latin1_General_BIN,N,1))
  FOR XML PATH(''),TYPE
).value('.[1]','varchar(8000)'));
GO

这是你可以使用的改编。

WITH E1(N) AS (
    SELECT N FROM (VALUES (0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) AS X(N)
)
SELECT      ProductData.Customer_ID,
            CASE
                WHEN ProductData.Product_Title = 'A_Title' AND ProductData.Product_Category != 'A_Category' THEN x.NewString
                WHEN ProductData.Product_Category = 'A_Category' THEN 'A_Category' 
                ELSE 'R_Category' END AS R_Category
FROM        ProductData
CROSS APPLY (SELECT NewString =((SELECT SUBSTRING(Product_Category,N,1)
                                  FROM (
                                      SELECT TOP(CONVERT(INT,LEN(Product_Category),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
                                      FROM E1 T1, E1 T2, E1 T3, E1 T4) AS iTally(N)
                                WHERE 0 = PATINDEX('%[^a-zA-Z ]%',SUBSTRING(Product_Category COLLATE Latin1_General_BIN,N,1))
                                FOR XML PATH(''),TYPE).value('.[1]','varchar(8000)'))) AS x;

正如肖恩和其他人所说的那样，你应该永久清理你的数据，而不是每次食用时都要清理食物。之前的SELECT语句可以很容易地转换为UPDATE。

WITH E1(N) AS (
    SELECT N FROM (VALUES (0),(0),(0),(0),(0),(0),(0),(0),(0),(0)) AS X(N)
)
UPDATE ProductData SET 
    Product_Category = CASE
                WHEN ProductData.Product_Title = 'A_Title' AND ProductData.Product_Category != 'A_Category' THEN x.NewString
                WHEN ProductData.Product_Category = 'A_Category' THEN 'A_Category' 
                ELSE 'R_Category' END 
FROM        ProductData
CROSS APPLY (SELECT NewString =((SELECT SUBSTRING(Product_Category,N,1)
                                  FROM (
                                      SELECT TOP(CONVERT(INT,LEN(Product_Category),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
                                      FROM E1 T1, E1 T2, E1 T3, E1 T4) AS iTally(N)
                                WHERE 0 = PATINDEX('%[^a-zA-Z ]%',SUBSTRING(Product_Category COLLATE Latin1_General_BIN,N,1))
                                FOR XML PATH(''),TYPE).value('.[1]','varchar(8000)'))) AS x;

SELECT * FROM ProductData;

Answer 2

您的更新代码工作正常，您只需处理如下所示的循环：

declare @i int
set @i = 1

while @i is not null
begin
declare @ids table (id int);
delete from @ids
set @i = null
        update  tb
        set val = replace(val, substring(val, patindex('%[^a-zA-Z ]%', val), 1), '')
        OUTPUT INSERTED.id INTO @ids
        where patindex('%[^a-zA-Z ]%', val) > 0

select  top 1 @i = id
from    @ids
end