Oracle SQL查询从包含批号的字符串中查找最小值

Question

我在Oracle数据库中有一列ID，该列是一个字符串，其值类似859188_1、859188_2、859188_3，...，859188_n。 _之后的值是批号，即1、2、3，...，n。 我需要根据该批号选择最小编号。 最小值是859188_1。

Answer 1

尝试...

 select id
 from yourTable
 where to_number(regexp_substr(ID, '[^_]+$')) =
   (select min(to_number(regexp_substr(t2.ID, '[^_]+$')))
    from yourTable t2
   )

Answer 2

您需要根据_ 之后的部分选择最小值。

如果像您的示例一样，前六个字符都相同，则可以执行以下操作：

select min(id) keep (dense_rank first order by length(id) asc, id asc) as min_id
from t;

Answer 3

也许像这样...

with
     inputs ( id ) as (
       select '100_1'  from dual union all
       select '100_3'  from dual union all
       select '100_12' from dual union all
       select '101_3'  from dual union all
       select '101_5'  from dual union all
       select '101_9'  from dual
     )
-- end of test data; solution (SQL query) begins below this line
select   min(id) keep (dense_rank first 
                       order by to_number(substr(id, instr(id, '_') + 1))) as id
from     inputs
group by substr(id, 1, instr(id, '_') - 1)
;

ID
-----
100_1
101_3