Question

我试图获取条件为“仅当字符串在第4位和第5位包含低位字符时才获取数据”的数据。以下是条件：

and ascii(substr(RAP01.CRDVER,4,1)) between 97 and 122
and ascii(substr(RAP01.CRDVER,5,1)) between 97 and 122;

表名RAP01和列名CRDVER。

但是它没有获取所有必需的数据。这种方法正确吗？

Answer 1

这个怎么样？键是第8行-查询将返回其第4和第5个字符（substr(col, 4, 2)）为小写字母（[a-z]）的字符串（c表示< em> search 区分大小写）。

SQL> with test (col) as
  2    (select '12Bcfx23' from dual union all
  3     select '123456'   from dual union all
  4     select 'ABCDEFGH' from dual
  5    )
  6  select col, substr(col, 4, 2) sub
  7  from test
  8  where regexp_like(substr(col, 4, 2), '[a-z]', 'c');

COL      SU
-------- --
12Bcfx23 cf

SQL>

Answer 2

小写字母是ASCII的子集吗？否
我可以使用ASCII识别小写吗？否

我怎么知道一个字符串是否小写？如果UPPER of string与string不同，则使用小写字母。

Sample：

create table t1 ( a varchar(100) )\\

insert into t1 (a) values ( 'A' )\\
insert into t1 (a) values ( 'a' )\\
insert into t1 (a) values ( 'å' )\\
insert into t1 (a) values ( 'æ' )\\

select (case when a = upper( a )                  <-- compare with upper
        then a || ' Is Upper' 
        else a || ' Has lower' end) as r_upper,

       (case when not regexp_like(a, '[a-z]', 'c') <-- using ascii
        then a || ' Is Upper' 
        else a || ' Has lower' end) as r_reg

       from t1\\

R_UPPER     | R_REG 
-------------------------
A Is Upper  | A Is Upper
a Has lower | a Has lower
å Has lower | å Is Upper (¹)
æ Has lower | æ Is Upper (¹)

（¹）使用ASCII错误的结果。

仅当字段在字符串中包含任何小写字母时才获取数据

2 个答案: