是否有一个函数来检查给定的字符串模式是否有效

Question

我需要一个 Oracle 函数来检查给定的输入字符串是否有效。

例如。输入字符串为50-100,145,153

函数应该检查

1. num1 num2 在 num1-num2
2. 字符串模式应始终为num1-num2,num3,num4

谢谢

Answer 1

没有内置函数，但您可以使用正则表达式。例如（只有第一行有效）：

SQL> with test (col) as
  2    (select '50-100,145,153' from dual union all
  3     select '50-49,145,153'  from dual union all
  4     select 'a-2,b,200'      from dual union all
  5     select '10-20,30'       from dual union all
  6     select '1,2-3,4'        from dual
  7    )
  8  select col
  9  from test
 10  where regexp_like(col, '^\d+-\d+,\d+,\d+$')
 11    and to_number(regexp_substr(col, '\w+', 1, 1)) < to_number(regexp_substr(col, '\w+', 1, 2));

COL
--------------
50-100,145,153

SQL>

Answer 2

我会使用这种方法：

with test (col) as
  (select '50-100,145,153' from dual union all  -- ok
   select '50-49,145,153'  from dual union all
   select 'a-2,b,200'      from dual union all
   select '10-20,30'       from dual union all  -- ok
   select '1,2-3,4'        from dual union all  -- ok
   -- additional test values:
   select '1,2,3,7-8,100,120-130,200'  from dual union all -- ok
   select '1-3,7-8,120-130,200'        from dual union all -- ok
   select '1,2,3,8-7,100,120-130,200'  from dual union all -- nope
   select '1,2,3,7-8,100,130-120,200'  from dual union all -- nope
   select '1,2,3,7-8,100,,,120-z,200'  from dual union all -- nope
   select '1,2,3,7-8,100,,,120,200'    from dual           -- nope
  )
select col
from test
where regexp_like(col, '^(((\d+-\d+)|\d+),?)+$')
  and (select 
          count(*)
       from dual
         where to_number(regexp_substr(col,'(\d+)-(\d+)',1,level,null,1))
             > to_number(regexp_substr(col,'(\d+)-(\d+)',1,level,null,2))
       connect by level<=regexp_count(col,'(\d+)-(\d+)')
      ) = 0;

1. regexp_like(col, '^(((\d+-\d+)|\d+),?)+$') 检查 col 是否仅包含 2 个模式：\d+-\d+ 和 \d+，它们之间用逗号分隔。

2. 在子查询中我们检查是否有num1>num2