OPEN emp_refcur FOR {plsql variable} 给出错误

Question

我是plsql开发的新手。

我在 plsql 变量（有我的动态 SQL 查询）上打开游标时遇到问题。我相信我在使用 ORACLE 12。

详情如下：

emp_refcur      SYS_REFCURSOR; -- Cursor declaration

component_sql:= 'select * from emp'; -- Base SQL

-- dynamic sql based on business logic
IF SOME_CONDITION THEN
  filters:= ' where DEP IN (''ABC'',''DEF'')';
ELSE
  filters:= ' where age>50';

component_sql:= component_sql||filters; -- appending filter to my base sql

OPEN emp_refcur FOR component_sql; -- opening the cursor
     LOOP
        FETCH emp_refcur INTO result;
            EXIT WHEN emp_refcur%NOTFOUND;
            dbms_output.put_line(result);
     END LOOP;
    CLOSE emp_refcur;

编译此程序在第 'OPEN emp_refcur FOR component_sql' 行显示错误，错误是

Error(90,9): PL/SQL: Statement ignored
Error(90,29): PLS-00382: expression is of wrong type

我不想使用

这样的绑定值

'OPEN emp_refcur FOR p_query_string USING p_deptno, p_sal;'

我尝试了多种方法

OPEN emp_refcur FOR ''||component_sql||''; -- This approach is not causing compilation error, but running the procedure resulting 

ORA-00900: invalid SQL statement

和

OPEN emp_refcur FOR 'select * from emp'||filters; -- This is resulting the error 
ORA-00900: invalid SQL statement

不确定我在这里遗漏了什么。请帮忙。

注意：如果有任何 SQL 查询语法错误，请忽略。因为我在附加过滤器后打印的 SQL 执行正常并在我单独运行时得到结果。

Answer 1

我试过你的代码，没有问题。 PLS-00382: 表达式类型错误 --> 这是语法错误。它与绑定变量无关。结果声明是什么？我没有在片段中看到。

PLS-00382: expression is of wrong type

Cause: An expression has the wrong datatype for the context in which it was found.

Action: Change the datatype of the expression. You might want to use datatype conversion functions.



Declare 
  emp_refcur SYS_REFCURSOR;
  filters varchar2(100);
  component_sql varchar2(100);
  result varchar2(20);

    Begin
    component_sql:= 'select 1 from dual'; -- Base SQL

    -- dynamic sql based on business logic
    IF 1=1 THEN
      filters:= ' UNION ALL SELECT 2 from dual';
    ELSE
      filters:= ' where age>50';
    End if;
    component_sql:= component_sql||filters; -- appending filter to my base sql
    OPEN emp_refcur FOR component_sql ; -- opening the cursor
         LOOP
            FETCH emp_refcur INTO result;
                EXIT WHEN emp_refcur%NOTFOUND;
                dbms_output.put_line(result);
         END LOOP;
        CLOSE emp_refcur;
    END;

OPEN emp_refcur FOR {plsql variable} 给出错误

OPEN emp_refcur FOR {plsql variable} giving error

sql

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