学步园

1、存储过程判断对象是否存在并执行DDL：

DECLARE
  V_COUNT INTEGER := 0;
BEGIN
  SELECT COUNT(*)
    INTO V_COUNT
    FROM USER_OBJECTS US
   WHERE US.OBJECT_NAME = 'GET_CHANGE_REC_ID'
     AND US.OBJECT_TYPE = 'PROCEDURE';
  IF V_COUNT > 0 THEN
    EXECUTE IMMEDIATE 'DROP PROCEDURE GET_CHANGE_REC_ID';  
  END IF;
END;
/

2、游标试用：

创建数据：

CREATE TABLE TBL_TEST
(
U_ID NUMBER(10) PRIMARY KEY,
U_NAME VARCHAR2(100)
);

BEGIN
 FOR I IN 1..20 LOOP
  INSERT INTO TBL_TEST VALUES(I,'NAME'||I);
 END LOOP;
 COMMIT;
END;
/

执行命令“SET SERVEROUTPUT ON”，打开输出

以游标的形式进行ID的累加：

DECLARE
 V_TOTAL INTEGER:=0;
BEGIN
 FOR R IN (SELECT * FROM TBL_TEST) LOOP
  V_TOTAL:=V_TOTAL+R.U_ID;
 END LOOP;
 DBMS_OUTPUT.put_line('V_TOTAL:'||V_TOTAL);
END;
/

在游标中设定参数：

DECLARE
  V_TOTAL INTEGER := 0;
  CURSOR C(V_ID INTEGER := 10) IS SELECT * FROM TBL_TEST WHERE U_ID < V_ID;
BEGIN
  FOR R IN C LOOP
    V_TOTAL := V_TOTAL + R.U_ID;
  END LOOP;
  DBMS_OUTPUT.PUT_LINE('V_TOTAL:' || V_TOTAL);
EXCEPTION
  WHEN OTHERS THEN
    IF C%ISOPEN THEN
      CLOSE C;
    END IF;
END;
/

输入输出参数：

CREATE OR REPLACE PROCEDURE P_TEST(V1 IN INTEGER,
                                   V2 IN INTEGER,
                                   S  OUT INTEGER) IS
BEGIN
  S := V1 + V2;
END;
/


-- 调用
DECLARE
  S INTEGER := 0;
BEGIN
  P_TEST(1, 2,S);
  DBMS_OUTPUT.PUT_LINE('SUM:' || S);
END;
/

 只有输入参数：

CREATE OR REPLACE PROCEDURE P_TEST(V1 IN INTEGER, V2 IN INTEGER) IS
BEGIN
  DBMS_OUTPUT.PUT_LINE('SUM:' || (V1 + V2));
END;
/

EXEC P_TEST(1,2);-- 脚本调用

如果出现编译错误，可以执行“SHOW ERRORS”来查看错误明细