在 Oracle IN 子句中使用替换变量

Question

我正在尝试编写一个简单的查询，其中要求使用一个替换变量，该变量可用于为用于过滤查询的列输入多个可能的值。

要求是产生以下查询

select
CONTRACT, 
ORDER_NO,
CUSTOMER_NO
from CUSTOMER_ORDER
where state='Picked'
and contract in ('ABC','DEF')

但合约值需要在运行时通过替换变量输入。我正在处理只能编写静态 SQL 查询（“select ..from..where..”）的限制，并且不能在 pl sql 块中编写动态代码。

所以，我尝试的是以下内容，

select
CONTRACT, 
ORDER_NO,
CUSTOMER_NO
from CUSTOMER_ORDER_JOIN
where contract in (select '''' || REPLACE('&CONTRACT',';',''',''') || '''' from dual)

当出现替换提示时，我输入 ABC;DEF

但这似乎不起作用。虽然当我单独运行以下内容时，

select '''' || REPLACE('&CONTRACT',';',''',''') || '''' from dual

我得到 'ABC','DEF' 作为结果。

为什么这不起作用？有没有办法达到我想要的结果？

谢谢

Answer 1

一种选择是将这些值拆分为行并将它们用作子查询。

基于 Scott 的 EMP 表的示例：

SQL> select ename, job, sal from emp;

ENAME      JOB              SAL
---------- --------- ----------
SMITH      CLERK            920
ALLEN      SALESMAN        1600
WARD       SALESMAN        1250
JONES      MANAGER         2975
MARTIN     SALESMAN        1250
BLAKE      MANAGER         2850
CLARK      MANAGER         2450
SCOTT      ANALYST         3000
KING       PRESIDENT      10000
TURNER     SALESMAN        1500
ADAMS      CLERK           1100
JAMES      CLERK            950
FORD       ANALYST         3000
MILLER     CLERK           1300

14 rows selected.

SQL> select ename, job, sal
  2  from emp
  3  where ename in (select regexp_substr(replace(q'[&&par_ename]', chr(39), ''), '[^,]+', 1, level)
  4                  from dual
  5                  connect by level <= regexp_count(q'[&&par_ename]', ',') + 1
  6                 );
Enter value for par_ename: 'SMITH','ALLEN'

ENAME      JOB              SAL
---------- --------- ----------
SMITH      CLERK            920
ALLEN      SALESMAN        1600

SQL>

---

或者，使用sys.odcivarchar2list:

SQL> select ename, job, sal
  2  from emp
  3  where ename in (select column_value
  4                  from table(sys.odcivarchar2list(&par_ename))
  5                 );
Enter value for par_ename: 'SMITH','ALLEN'

ENAME      JOB              SAL
---------- --------- ----------
SMITH      CLERK            920
ALLEN      SALESMAN        1600

SQL>

---

它也可以不带单引号：

SQL> Select ename, job, sal
  2      from emp
  3      where ename in (select regexp_substr(replace(q'[&&par_ename]', chr(39), ''), '[^,]+', 1, level)
  4                      from dual
  5                      connect by level <= regexp_count(q'[&&par_ename]', ',') + 1
  6                     );
Enter value for par_ename: SMITH,ALLEN,KING

ENAME      JOB              SAL
---------- --------- ----------
SMITH      CLERK            920
ALLEN      SALESMAN        1600
KING       PRESIDENT      10000

SQL>