如何从字符串中删除所有非字母的字符?

非字母数字呢?

这必须是一个自定义函数还是也有更通用的解决方案?


当前回答

DECLARE @vchVAlue NVARCHAR(255) = 'SWP, Lettering Position 1: 4 Ω, 2: 8 Ω, 3: 16 Ω, 4:  , 5:  , 6:  , Voltage Selector, Solder, 6, Step switch, : w/o fuseholder '


WHILE PATINDEX('%?%' , CAST(@vchVAlue AS VARCHAR(255))) > 0
  BEGIN
    SELECT @vchVAlue = STUFF(@vchVAlue,PATINDEX('%?%' , CAST(@vchVAlue AS VARCHAR(255))),1,' ')
  END 

SELECT @vchVAlue

其他回答

这个解决方案受到Allen先生的解决方案的启发,需要一个整数的Numbers表(如果您想进行具有良好性能的严肃查询操作,您应该手头有这个表)。它不需要CTE。您可以更改NOT IN(…)表达式以排除特定字符,或将其更改为IN(…)只保留某些字符的OR LIKE表达式。

SELECT (
    SELECT  SUBSTRING([YourString], N, 1)
    FROM    dbo.Numbers
    WHERE   N > 0 AND N <= CONVERT(INT, LEN([YourString]))
        AND SUBSTRING([YourString], N, 1) NOT IN ('(',')',',','.')
    FOR XML PATH('')
) AS [YourStringTransformed]
FROM ...

首先创建一个函数

CREATE FUNCTION [dbo].[GetNumericonly]
(@strAlphaNumeric VARCHAR(256))
RETURNS VARCHAR(256)
AS
BEGIN
     DECLARE @intAlpha INT
     SET @intAlpha = PATINDEX('%[^0-9]%', @strAlphaNumeric)
BEGIN
     WHILE @intAlpha > 0
   BEGIN
          SET @strAlphaNumeric = STUFF(@strAlphaNumeric, @intAlpha, 1, '' )
          SET @intAlpha = PATINDEX('%[^0-9]%', @strAlphaNumeric )
   END
END
RETURN ISNULL(@strAlphaNumeric,0)
END

现在把这个函数叫做

select [dbo].[GetNumericonly]('Abhi12shek23jaiswal')

它的结果是

1223
CREATE FUNCTION remove_spc_char(@str VARCHAR(MAX))
  RETURNS VARCHAR(MAX) 
AS
BEGIN
  DECLARE @resp    VARCHAR(MAX) = '';
  DECLARE @str_val   VARCHAR(MAX) = UPPER(@str);
  DECLARE @i       INTEGER= 1;
  DECLARE @v_asc   INTEGER;
   WHILE @i <= (LEN(@str_val))
   BEGIN
     SET @v_asc = (ASCII(SUBSTRING(@str_val, @i, 1))) 
        BEGIN
        IF @v_asc in (192,193,194,195,196,65) 
            begin
                SET @v_asc = 65;
                SET @resp = concat(@resp, CHAR(@v_asc));
            end;
        IF @v_asc in (200,201,202,203,233,69)
            begin
                SET @v_asc = 69;
                SET @resp = concat(@resp, CHAR(@v_asc));
            end;
        IF @v_asc in (204,205,206,207,296,73)
            begin
                SET @v_asc = 73;
                SET @resp = concat(@resp, CHAR(@v_asc));
            end;
        IF @v_asc in (210,211,212,213,214,79)
            begin
                SET @v_asc = 79;
                SET @resp = concat(@resp, CHAR(@v_asc));
            end;
        IF @v_asc in (217,218,219,220,85)
            begin
                SET @v_asc = 85;
                SET @resp = concat(@resp, CHAR(@v_asc));
            end;
        IF @v_asc in (199,231,67)
            begin
                SET @v_asc = 67;
                SET @resp = concat(@resp, CHAR(@v_asc));
            end;
        IF @v_asc in (209,78)
            begin
                SET @v_asc = 78;
                SET @resp = concat(@resp, CHAR(@v_asc));
            end;
        IF @v_asc in (924,181,358,216,222,330,272,208,198,42,37,38,34,36,35,
64,33,39,41,40,43,61,95,45,62,60,63,47,176,183,124,166,174,359,248,254,
180,170,186,126,312,331,273,172,178,179,163,162,123,91,93,125,92,167,240,
223,230,171,187,169,185,168)
            begin
                SET @resp = concat(@resp, '');
            end;
        ELSE 
            begin
                if @v_asc not in (65,67,69,73,78,79,85)
                begin
                    SET @resp = concat(@resp, CHAR(@v_asc));
                end;
            end;
        END;
      SET @i = @i + 1
    END;
    RETURN @resp;
END;

我刚在Oracle 10g中找到了这个,如果你用的就是它的话。为了进行电话号码比较,我必须去掉所有的特殊字符。

regexp_replace(c.phone, '[^0-9]', '')

Here's a solution that doesn't require creating a function or listing all instances of characters to replace. It uses a recursive WITH statement in combination with a PATINDEX to find unwanted chars. It will replace all unwanted chars in a column - up to 100 unique bad characters contained in any given string. (E.G. "ABC123DEF234" would contain 4 bad characters 1, 2, 3 and 4) The 100 limit is the maximum number of recursions allowed in a WITH statement, but this doesn't impose a limit on the number of rows to process, which is only limited by the memory available. If you don't want DISTINCT results, you can remove the two options from the code.

-- Create some test data:
SELECT * INTO #testData 
FROM (VALUES ('ABC DEF,K.l(p)'),('123H,J,234'),('ABCD EFG')) as t(TXT)

-- Actual query:
-- Remove non-alpha chars: '%[^A-Z]%'
-- Remove non-alphanumeric chars: '%[^A-Z0-9]%'
DECLARE @BadCharacterPattern VARCHAR(250) = '%[^A-Z]%';

WITH recurMain as (
    SELECT DISTINCT CAST(TXT AS VARCHAR(250)) AS TXT, PATINDEX(@BadCharacterPattern, TXT) AS BadCharIndex
    FROM #testData
    UNION ALL
    SELECT CAST(TXT AS VARCHAR(250)) AS TXT, PATINDEX(@BadCharacterPattern, TXT) AS BadCharIndex
    FROM (
        SELECT 
            CASE WHEN BadCharIndex > 0 
                THEN REPLACE(TXT, SUBSTRING(TXT, BadCharIndex, 1), '')
                ELSE TXT 
            END AS TXT
        FROM recurMain
        WHERE BadCharIndex > 0
    ) badCharFinder
)
SELECT DISTINCT TXT
FROM recurMain
WHERE BadCharIndex = 0;