找出字符串是否只包含ASCII字符

你可以用 TRANSLATE 这样做。基本上, translate 去掉所有的ASCII可打印字符(没有那么多字符),看看你还剩下什么。

下面是一个执行此操作的查询:

WITH input ( p_string_to_test) AS ( 
SELECT 'This this string' FROM DUAL UNION ALL
SELECT 'Test this ' || CHR(7) || ' string too!' FROM DUAL UNION ALL
SELECT 'xxx' FROM DUAL)
SELECT p_string_to_test, 
       case when translate(p_string_to_test, 
       chr(0) || q'[ !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~]', 
       chr(0)) is null then 'Yes' else 'No' END is_ascii
FROM input;

+-------------------------+----------+
|    P_STRING_TO_TEST     | IS_ASCII |
+-------------------------+----------+
| This this string        | Yes      |
| Test this  string too!  | No       |
| xxx                     | Yes      |
+-------------------------+----------+

ASCII 上限为的函数 127 可用于:

declare
    str nvarchar2(100) := '\xyz~*-=)(/&%+$#£>|"éß';
    a   nvarchar2(1);
    b   number := 0;
begin
    for i in 1..length(str)
    loop                 
      a := substrc(str,i,1);
      b := greatest(ascii(a),b);      
    end loop;

    if b < 128 then  
     dbms_output.put_line('String is composed of Pure ASCII characters');
    else
     dbms_output.put_line('String has non-ASCII characters');      
    end if; 
end;

我想我要这两个中的一个

IF CONVERT(str, 'US7ASCII') = str THEN
    DBMS_OUTPUT.PUT_LINE('Pure ASCII');
END IF;



IF ASCIISTR(REPLACE(str, '\', '/')) = REPLACE(str, '\', '/') THEN
    DBMS_OUTPUT.PUT_LINE('Pure ASCII');
END IF;