Como verificar caracteres não-ASCII

Qual é a melhor maneira de verificar se um campo VARCHAR possui caracteres não-ASCII?
CHAR(1)completamente CHAR(31)e CHAR(127)completamente CHAR(255).

Tentei usar PATINDEXe encontrei o seguinte problema.

A verificação da faixa inferior funcionou corretamente.

SELECT *      
FROM mbrnotes      
WHERE PATINDEX('%[' + CHAR(1)+ '-' +CHAR(31)+']%',LINE_TEXT) > 0  

Meus dados tinham três registros com 0x1E e todos os três foram retornados.

Mas quando eu verifico apenas a faixa superior:

SELECT *      
FROM mbrnotes      
WHERE PATINDEX('%[' + CHAR(127)+ '-' +CHAR(255)+']%',LINE_TEXT) > 0 

Ele retorna perto de todos os registros da tabela (contagem da tabela 170737 e contagem retornada 170735) e, como meus dados não tinham nenhum valor nesse intervalo, eu acho que não deveria ter retornado nenhum registro.

Intervalos na sintaxe de padrão usam as regras de classificação do seu agrupamento.

Use uma cláusula de classificação binária para que o intervalo seja ordenado pelo código de caractere.

(Eu também mudei para LIKE como acho mais óbvio que PATINDEX > 0)

SELECT *      
FROM mbrnotes      
WHERE LINE_TEXT LIKE '%[' + CHAR(127)+ '-' +CHAR(255)+']%'  COLLATE Latin1_General_100_BIN2

Se você é como eu e se cansou ao longo dos anos pesquisando esses personagens nos terríveis dados da sua empresa, pode usar essa função ou reescrevê-la para seu próprio objetivo. É reconhecidamente prolixo, mas dá o passo extra de identificar caracteres especiais, se você quiser - descomente as linhas 19 a 179 para fazer isso.

Se a sequência não contiver valores ASCII não imprimíveis ou estendidos, ela retornará NULL.

CREATE FUNCTION [dbo].[Find_Invalid_Chars]
(
    @SearchString VARCHAR(8000)
)
RETURNS VARCHAR(8000)
AS
BEGIN
    DECLARE @CharPosition INT, @CharVal VARCHAR(100), @ReturnVal VARCHAR(8000) = '', @isValid BIT = 1 -- Start as valid

    SET @CharPosition = 1

    WHILE @CharPosition <= DATALENGTH(@SearchString)
    BEGIN
    IF (ASCII(SUBSTRING(@SearchString, @CharPosition, 1)) NOT BETWEEN (32) AND (127))
        BEGIN
            SET @CharVal = '[' + CAST(ASCII(SUBSTRING(@SearchString, @CharPosition, 1)) AS VARCHAR(3)) + ']'
            SET @isValid = 0
            ---- Non-Printables
            --SET @CharVal = REPLACE(@CharVal, '[0]', '[NUL]')
            --SET @CharVal = REPLACE(@CharVal, '[1]', '[SOH]')
            --SET @CharVal = REPLACE(@CharVal, '[2]', '[STX]')
            --SET @CharVal = REPLACE(@CharVal, '[3]', '[ETX]')
            --SET @CharVal = REPLACE(@CharVal, '[4]', '[EOT]')
            --SET @CharVal = REPLACE(@CharVal, '[5]', '[ENQ]')
            --SET @CharVal = REPLACE(@CharVal, '[6]', '[ACK]')
            --SET @CharVal = REPLACE(@CharVal, '[7]', '[BEL]')
            --SET @CharVal = REPLACE(@CharVal, '[8]', '[BS]')
            --SET @CharVal = REPLACE(@CharVal, '[9]', '[HT]')
            --SET @CharVal = REPLACE(@CharVal, '[10]', '[LF]')
            --SET @CharVal = REPLACE(@CharVal, '[11]', '[VT]')
            --SET @CharVal = REPLACE(@CharVal, '[12]', '[FF]')
            --SET @CharVal = REPLACE(@CharVal, '[13]', '[CR]')
            --SET @CharVal = REPLACE(@CharVal, '[14]', '[SO]')
            --SET @CharVal = REPLACE(@CharVal, '[15]', '[SI]')
            --SET @CharVal = REPLACE(@CharVal, '[16]', '[DLE]')
            --SET @CharVal = REPLACE(@CharVal, '[17]', '[DC1]')
            --SET @CharVal = REPLACE(@CharVal, '[18]', '[DC2]')
            --SET @CharVal = REPLACE(@CharVal, '[19]', '[DC3]')
            --SET @CharVal = REPLACE(@CharVal, '[20]', '[DC4]')
            --SET @CharVal = REPLACE(@CharVal, '[21]', '[NAK]')
            --SET @CharVal = REPLACE(@CharVal, '[22]', '[SYN]')
            --SET @CharVal = REPLACE(@CharVal, '[23]', '[ETB]')
            --SET @CharVal = REPLACE(@CharVal, '[24]', '[CAN]')
            --SET @CharVal = REPLACE(@CharVal, '[25]', '[EM]')
            --SET @CharVal = REPLACE(@CharVal, '[26]', '[SUB]')
            --SET @CharVal = REPLACE(@CharVal, '[27]', '[ESC]')
            --SET @CharVal = REPLACE(@CharVal, '[28]', '[FS]')
            --SET @CharVal = REPLACE(@CharVal, '[29]', '[GS]')
            --SET @CharVal = REPLACE(@CharVal, '[30]', '[RS]')
            --SET @CharVal = REPLACE(@CharVal, '[31]', '[US]')
            ---- Extended Ascii
            --SET @CharVal = REPLACE(@CharVal, '[128]', '[€]')
            --SET @CharVal = REPLACE(@CharVal, '[129]', '[]]')
            --SET @CharVal = REPLACE(@CharVal, '[130]', '[‚]')
            --SET @CharVal = REPLACE(@CharVal, '[131]', '[ƒ]')
            --SET @CharVal = REPLACE(@CharVal, '[132]', '[„]')
            --SET @CharVal = REPLACE(@CharVal, '[133]', '[…]')
            --SET @CharVal = REPLACE(@CharVal, '[134]', '[†]')
            --SET @CharVal = REPLACE(@CharVal, '[135]', '[‡]')
            --SET @CharVal = REPLACE(@CharVal, '[136]', '[ˆ]')
            --SET @CharVal = REPLACE(@CharVal, '[137]', '[‰]')
            --SET @CharVal = REPLACE(@CharVal, '[138]', '[Š]')
            --SET @CharVal = REPLACE(@CharVal, '[139]', '[‹]')
            --SET @CharVal = REPLACE(@CharVal, '[140]', '[Œ]')
            --SET @CharVal = REPLACE(@CharVal, '[141]', '[]]')
            --SET @CharVal = REPLACE(@CharVal, '[142]', '[Ž]')
            --SET @CharVal = REPLACE(@CharVal, '[143]', '[]]')
            --SET @CharVal = REPLACE(@CharVal, '[144]', '[]]')
            --SET @CharVal = REPLACE(@CharVal, '[145]', '[‘]')
            --SET @CharVal = REPLACE(@CharVal, '[146]', '[’]')
            --SET @CharVal = REPLACE(@CharVal, '[147]', '[“]')
            --SET @CharVal = REPLACE(@CharVal, '[148]', '[”]')
            --SET @CharVal = REPLACE(@CharVal, '[149]', '[•]')
            --SET @CharVal = REPLACE(@CharVal, '[150]', '[–]')
            --SET @CharVal = REPLACE(@CharVal, '[151]', '[—]')
            --SET @CharVal = REPLACE(@CharVal, '[152]', '[˜]')
            --SET @CharVal = REPLACE(@CharVal, '[153]', '[™]')
            --SET @CharVal = REPLACE(@CharVal, '[154]', '[š]')
            --SET @CharVal = REPLACE(@CharVal, '[155]', '[›]')
            --SET @CharVal = REPLACE(@CharVal, '[156]', '[œ]')
            --SET @CharVal = REPLACE(@CharVal, '[157]', '[]]')
            --SET @CharVal = REPLACE(@CharVal, '[158]', '[ž]')
            --SET @CharVal = REPLACE(@CharVal, '[159]', '[Ÿ]')
            --SET @CharVal = REPLACE(@CharVal, '[160]', '[]]')
            --SET @CharVal = REPLACE(@CharVal, '[161]', '[¡]')
            --SET @CharVal = REPLACE(@CharVal, '[162]', '[¢]')
            --SET @CharVal = REPLACE(@CharVal, '[163]', '[£]')
            --SET @CharVal = REPLACE(@CharVal, '[164]', '[¤]')
            --SET @CharVal = REPLACE(@CharVal, '[165]', '[¥]')
            --SET @CharVal = REPLACE(@CharVal, '[166]', '[¦]')
            --SET @CharVal = REPLACE(@CharVal, '[167]', '[§]')
            --SET @CharVal = REPLACE(@CharVal, '[168]', '[¨]')
            --SET @CharVal = REPLACE(@CharVal, '[169]', '[©]')
            --SET @CharVal = REPLACE(@CharVal, '[170]', '[ª]')
            --SET @CharVal = REPLACE(@CharVal, '[171]', '[«]')
            --SET @CharVal = REPLACE(@CharVal, '[172]', '[¬]')
            --SET @CharVal = REPLACE(@CharVal, '[173]', '[]]')
            --SET @CharVal = REPLACE(@CharVal, '[174]', '[®]')
            --SET @CharVal = REPLACE(@CharVal, '[175]', '[¯]')
            --SET @CharVal = REPLACE(@CharVal, '[176]', '[°]')
            --SET @CharVal = REPLACE(@CharVal, '[177]', '[±]')
            --SET @CharVal = REPLACE(@CharVal, '[178]', '[²]')
            --SET @CharVal = REPLACE(@CharVal, '[179]', '[³]')
            --SET @CharVal = REPLACE(@CharVal, '[180]', '[´]')
            --SET @CharVal = REPLACE(@CharVal, '[181]', '[µ]')
            --SET @CharVal = REPLACE(@CharVal, '[182]', '[¶]')
            --SET @CharVal = REPLACE(@CharVal, '[183]', '[·]')
            --SET @CharVal = REPLACE(@CharVal, '[184]', '[¸]')
            --SET @CharVal = REPLACE(@CharVal, '[185]', '[¹]')
            --SET @CharVal = REPLACE(@CharVal, '[186]', '[º]')
            --SET @CharVal = REPLACE(@CharVal, '[187]', '[»]')
            --SET @CharVal = REPLACE(@CharVal, '[188]', '[¼]')
            --SET @CharVal = REPLACE(@CharVal, '[189]', '[½]')
            --SET @CharVal = REPLACE(@CharVal, '[190]', '[¾]')
            --SET @CharVal = REPLACE(@CharVal, '[191]', '[¿]')
            --SET @CharVal = REPLACE(@CharVal, '[192]', '[À]')
            --SET @CharVal = REPLACE(@CharVal, '[193]', '[Á]')
            --SET @CharVal = REPLACE(@CharVal, '[194]', '[Â]')
            --SET @CharVal = REPLACE(@CharVal, '[195]', '[Ã]')
            --SET @CharVal = REPLACE(@CharVal, '[196]', '[Ä]')
            --SET @CharVal = REPLACE(@CharVal, '[197]', '[Å]')
            --SET @CharVal = REPLACE(@CharVal, '[198]', '[Æ]')
            --SET @CharVal = REPLACE(@CharVal, '[199]', '[Ç]')
            --SET @CharVal = REPLACE(@CharVal, '[200]', '[È]')
            --SET @CharVal = REPLACE(@CharVal, '[201]', '[É]')
            --SET @CharVal = REPLACE(@CharVal, '[202]', '[Ê]')
            --SET @CharVal = REPLACE(@CharVal, '[203]', '[Ë]')
            --SET @CharVal = REPLACE(@CharVal, '[204]', '[Ì]')
            --SET @CharVal = REPLACE(@CharVal, '[205]', '[Í]')
            --SET @CharVal = REPLACE(@CharVal, '[206]', '[Î]')
            --SET @CharVal = REPLACE(@CharVal, '[207]', '[Ï]')
            --SET @CharVal = REPLACE(@CharVal, '[208]', '[Ð]')
            --SET @CharVal = REPLACE(@CharVal, '[209]', '[Ñ]')
            --SET @CharVal = REPLACE(@CharVal, '[210]', '[Ò]')
            --SET @CharVal = REPLACE(@CharVal, '[211]', '[Ó]')
            --SET @CharVal = REPLACE(@CharVal, '[212]', '[Ô]')
            --SET @CharVal = REPLACE(@CharVal, '[213]', '[Õ]')
            --SET @CharVal = REPLACE(@CharVal, '[214]', '[Ö]')
            --SET @CharVal = REPLACE(@CharVal, '[215]', '[×]')
            --SET @CharVal = REPLACE(@CharVal, '[216]', '[Ø]')
            --SET @CharVal = REPLACE(@CharVal, '[217]', '[Ù]')
            --SET @CharVal = REPLACE(@CharVal, '[218]', '[Ú]')
            --SET @CharVal = REPLACE(@CharVal, '[219]', '[Û]')
            --SET @CharVal = REPLACE(@CharVal, '[220]', '[Ü]')
            --SET @CharVal = REPLACE(@CharVal, '[221]', '[Ý]')
            --SET @CharVal = REPLACE(@CharVal, '[222]', '[Þ]')
            --SET @CharVal = REPLACE(@CharVal, '[223]', '[ß]')
            --SET @CharVal = REPLACE(@CharVal, '[224]', '[à]')
            --SET @CharVal = REPLACE(@CharVal, '[225]', '[á]')
            --SET @CharVal = REPLACE(@CharVal, '[226]', '[â]')
            --SET @CharVal = REPLACE(@CharVal, '[227]', '[ã]')
            --SET @CharVal = REPLACE(@CharVal, '[228]', '[ä]')
            --SET @CharVal = REPLACE(@CharVal, '[229]', '[å]')
            --SET @CharVal = REPLACE(@CharVal, '[230]', '[æ]')
            --SET @CharVal = REPLACE(@CharVal, '[231]', '[ç]')
            --SET @CharVal = REPLACE(@CharVal, '[232]', '[è]')
            --SET @CharVal = REPLACE(@CharVal, '[233]', '[é]')
            --SET @CharVal = REPLACE(@CharVal, '[234]', '[ê]')
            --SET @CharVal = REPLACE(@CharVal, '[235]', '[ë]')
            --SET @CharVal = REPLACE(@CharVal, '[236]', '[ì]')
            --SET @CharVal = REPLACE(@CharVal, '[237]', '[í]')
            --SET @CharVal = REPLACE(@CharVal, '[238]', '[î]')
            --SET @CharVal = REPLACE(@CharVal, '[239]', '[ï]')
            --SET @CharVal = REPLACE(@CharVal, '[240]', '[ð]')
            --SET @CharVal = REPLACE(@CharVal, '[241]', '[ñ]')
            --SET @CharVal = REPLACE(@CharVal, '[242]', '[ò]')
            --SET @CharVal = REPLACE(@CharVal, '[243]', '[ó]')
            --SET @CharVal = REPLACE(@CharVal, '[244]', '[ô]')
            --SET @CharVal = REPLACE(@CharVal, '[245]', '[õ]')
            --SET @CharVal = REPLACE(@CharVal, '[246]', '[ö]')
            --SET @CharVal = REPLACE(@CharVal, '[247]', '[÷]')
            --SET @CharVal = REPLACE(@CharVal, '[248]', '[ø]')
            --SET @CharVal = REPLACE(@CharVal, '[249]', '[ù]')
            --SET @CharVal = REPLACE(@CharVal, '[250]', '[ú]')
            --SET @CharVal = REPLACE(@CharVal, '[251]', '[û]')
            --SET @CharVal = REPLACE(@CharVal, '[252]', '[ü]')
            --SET @CharVal = REPLACE(@CharVal, '[253]', '[ý]')
            --SET @CharVal = REPLACE(@CharVal, '[254]', '[þ]')
            --SET @CharVal = REPLACE(@CharVal, '[255]', '[ÿ]')
        END
    ELSE
        BEGIN
            SET @CharVal = SUBSTRING(@SearchString, @CharPosition, 1)
        END

    SET @ReturnVal = @ReturnVal + @CharVal

    SET @CharPosition = @CharPosition + 1
    END

IF (@isValid = 1) SET @ReturnVal = NULL

RETURN @ReturnVal

END

E então, chame assim:

SELECT BadString, dbo.Find_Invalid_Chars(BadString) [Invalid Characters]
FROM #tmp_Table tmp_mc
WHERE dbo.Find_Invalid_Chars(BadString) IS NOT NULL

Saída de amostra:

Ou