DECLARE @s VARCHAR(MAX)= 'AbcdEf奧奧' --待截取字符串 
DECLARE @temp VARCHAR(MAX)=''   --臨時(shí)變量 
SELECT @temp=@temp+SUBSTRING(ch, sv.number, 1)  
FROM  (SELECT @s AS ch) t 
    CROSS APPLY [master].dbo.spt_values AS sv  
WHERE sv.type = 'P'  
    AND sv.number BETWEEN 1 AND LEN(ch)  
    AND ASCII(SUBSTRING(ch, sv.number, 1)) BETWEEN ASCII('a') AND ASCII('z')  
SELECT @temp 

SELECT @temp=@temp+SUBSTRING(ch, sv.number, 1)  
FROM  (SELECT @s AS ch) t 
    CROSS APPLY [master].dbo.spt_values AS sv  
WHERE sv.type = 'P'  
    AND sv.number BETWEEN 1 AND LEN(ch)  
    AND ASCII(SUBSTRING(ch, sv.number, 1)) BETWEEN ASCII('A') AND ASCII('Z')  
SELECT @temp