Question

我的oracle数据库中有一个表，其中包含varchar2列＆＃39; Detail_Number＆＃39;记录如下所示 -

Detail_Number
--------------
P1464187
1-17J3P
VAR1460621
P15000566
VRH-P146310034
RH-73082_SS1
19502744

现在，我想使用一个case语句，它只返回特殊字符＆＃39; _＆＃39;之前的Detail_Number列的一部分。如果存在特殊字符。否则，只需返回Detail_Number。

我写的案例陈述是 -

CASE
  WHEN INSTR(A.AGREEMENT_NUMBER, '_') IS NOT NULL THEN SUBSTR(A.AGREEMENT_NUMBER, 0, INSTR(A.AGREEMENT_NUMBER, '_')-1)
  WHEN INSTR(A.AGREEMENT_NUMBER, '_') = 0 THEN A.AGREEMENT_NUMBER
  --ELSE A.AGREEMENT_NUMBER
END AS Output

查询结果如下 -

Detail_Number   Output
-------------   --------
P1464187    
1-17J3P 
VAR1460621  
P15000566   
VRH-P146310034  
RH-73082_SS1    RH-73082
19502744

在这里，我得到的是＆＃39; _＆＃39;被跳过了。但是，如果＆＃39; _＆＃39;不存在，它返回null。请你帮我一下。

感谢。

Answer 1

你的意思是？

SQL> with
  2    data as (select 'P1464187' t# from dual union all
  3             select '1-17J3P' t# from dual union all
  4             select 'VAR1460621' t# from dual union all
  5             select 'P15000566' t# from dual union all
  6             select 'VRH-P146310034' t# from dual union all
  7             select 'RH-73082_SS1' t# from dual union all
  8             select '19502744' t# from dual)
  9  select
 10    substr(t#, 1, instr(t# || '_', '_') - 1)
 11  from
 12    data;

SUBSTR(T#,1,INSTR(T#||'_','_')-1)
--------------------------------------------------------
P1464187
1-17J3P
VAR1460621
P15000566
VRH-P146310034
RH-73082
19502744

7 rows selected.

Answer 2

使用REGEXP_REPLACE的选项（在大型建筑物中可能不像Sanders INSTR选项那样有效;）（但仍然有效）

  with w_data as ( 
        select rtrim('P1464187      ') c from dual union all
        select rtrim('1-17J3P       ') c from dual union all
        select rtrim('VAR1460621    ') c from dual union all
        select rtrim('P15000566     ') c from dual union all
        select rtrim('VRH-P146310034') c from dual union all
        select rtrim('RH-73082_SS1  ') c from dual union all
        select rtrim('19502744      ') c from dual
        )
  Select c, regexp_replace(c, '^(.*)[_$]','\1') d
  from w_data;


  C              D
  -------------- ----------------------------------------
  P1464187       P1464187
  1-17J3P        1-17J3P
  VAR1460621     VAR1460621
  P15000566      P15000566
  VRH-P146310034 VRH-P146310034
  RH-73082_SS1   RH-73082SS1
  19502744       19502744

  7 rows selected.

案件情况＆amp;在oracle中使用instring函数

2 个答案: