在Oracle中遍历显式游标

Question

如何遍历例如从查询创建的隐式游标？

这是示例代码：

SERVEROUTPUT on;

DECLARE      
  TYPE ref_cursor IS REF CURSOR;
  cur REF_CURSOR;

BEGIN
  OPEN cur FOR 'SELECT i.item_no, 
                       i.item_descr 
                  FROM ITEMS i 
                 WHERE i.item_no in (1,2,3)';

  ... loop statement to print all item descriptions?

END;

Answer 1

这是允许动态SQL的方法。您可以根据需要在代码中构建查询字符串（适用于有关SQL注入的常规警告）。

DECLARE      
  TYPE ref_cursor IS REF CURSOR;
  cur REF_CURSOR;

  d_item_no  items.item_no%TYPE;
  d_item_descr  items.item_descr%TYPE;

BEGIN
  OPEN cur FOR 'SELECT i.item_no, 
                       i.item_descr 
                  FROM ITEMS i 
                 WHERE i.item_no in (1,2,3)';
  LOOP
    FETCH cur INTO d_item_no, d_item_descr;
    EXIT WHEN cur%NOTFOUND;
    dbms_output.put_line( d_item_no||' '||d_item_descr );
  END LOOP;

  CLOSE cur;
END;
/