PLSQL 游标的使用

1.游标特性
%FOUND
%OPEN
%NOTFOUND
%ROWCOUNT

2.静态显示游标
DECLARE
  id item.item_id%TYPE;
  title varchar2(60);
  CURSOR c IS
    SELECT item_id,item_title
    FROM item
BEGIN
  OPEN c;
  LOOP
    FETCH c INTO id,title;
    EXIT WHEN c%NOTFOUND;
    DBMS_OUTPUT.PUT_LINE('id||'   '||title);
  END LOOP;
  CLOSE c;
END;

游标FOR循环
1.
DECLARE
  CURSOR c IS
    SELECT item_id AS id,item_title AS title
    FROM item
BEGIN
　FOR i IN c LOOP
    DBMS_OUTPUT.PUT_LINE(i.id||'  '||i.title);
  END LOOP;
END;

2.简单游标循环，需显式打开和关闭游标
DECLARE
 TYPE item_record IS RECORD (
   id NUMBER,
   title VARCAHR2(60));
 item ITERM_RECORD;
 CURSOR c IS
   SELECT item_id,item_title
   FROM item;

 BEGIN
   OPEN c;
   LOOP
     FETCH c INTO item;
     EXIT WHEN c%NOTFOUND;
     DBMS_OUTPUT.PUT_LINE(item.itemid||'   '||item.item_title);
   END LOOP;
   CLOSE c;
 END;

 3.
DECLARE
 TYPE item_record IS RECORD (
   id NUMBER,
   title VARCAHR2(60));
 item ITERM_RECORD;
 CURSOR c IS
   SELECT item_id,item_title
   FROM item;
 BEGIN
  FOR i IN c LOOP
    item := i;
    DBMS_OUTPUT.PUT_LINE(item.itemid||'   '||item.item_title);
  END LOOP;
 END;

 4.带参数的游标(简单循环）
 DECLARE
   lowend NUMBER;
   highend NUMBER;
   item_id NUMBER := 1012;

   TYPE item_record IS RECORD(
     id　NUMBER,
     title VARCHAR2(60));
   item ITEM_RECORD;
   CURSOR c(low_id NUMBER,high_id NUMBER) IS
     SELECT item_id,item_title
     FROM item
     WHERE item_id BETWEEN low_id AND high_id;

 BEGIN
   lowend := 1005;
   highend := 1021;
   OPEN c(lowend,highend);
   LOOP
      FETCH c INTO item;
      EXIT WHEN c%NOTFOUND;
      DBMS_OUTPUT.PUT_LINE(item.id || '  '|| item.title);
   END LOOP;
   CLOSE c;
 END;

5.带参数的游标(FOR 循环）
 DECLARE
   lowend NUMBER;
   highend NUMBER;
   item_id NUMBER := 1012;
   TYPE item_record IS RECORD(
     id　NUMBER,
     title VARCHAR2(60));
   item ITEM_RECORD;
   CURSOR c(low_id NUMBER,high_id NUMBER) IS
     SELECT item_id,item_title
     FROM item
     WHERE item_id BETWEEN low_id AND high_id;
 BEGIN
   lowend := 1005;
   highend := 1021;
   FOR i IN c(lowend,highend) LOOP
     item := i;
     DBMS_OUTPUT.PUT_LINE(item.id || '  '|| item.title);
 END;