Oracle OCP笔记(16)SQL与PL/SQL对象

Oracle OCP笔记(16)SQL与PL/SQL对象

1.SQL语言16条命令:

数据操纵语言(Data Manipulation Language, DML)命令:

·SELECT

·INSERT

·UPDATE

·DELETE

·MERGE

数据定义语言(Data Definition Language, DDL)命令:

·CREATE

·ALTER

·DROP

·RENAME

·TRUNCATE

·COMMENT

数据控制语言(Data Control Language, DCL)命令:

·GRANT

·REVOKE

事务控制语言(Transaction Control Language, TCL)命令:

·COMMIT

·ROLLBACK

·SAVEPOINT

2.PL/SQL对象

匿名块

存储过程(Procedure)

函数(Function)

包(包头Package、包体Package Body)

触发器(Trigger)

视图(View)

(1)匿名块

DECLARE

-- 声明部分 (程序未用到可不写)

BEGIN

-- 执行部分 (必需)

EXCEPTION

-- 异常处理 (不处理异常可不写)

END;

(2).存储过程(Procedure)

　 CREATE OR REPLACE PROCEDURE procedure_name

[(argument [IN | OUT | IN OUT] type,…)]

{IS | AS }

-- 变量定义，cursor ，子过程等

BEGIN

-- procedure body;

EXCEPTION

-- 例外处理

END [procedure_name];

(3).函数(Function)

CREATE [OR REPLACE] FUNCTION function_name

[(argument [IN | OUT | IN OUT] type,…)]

RETURN return_type {IS | AS}

-- 变量定义

BEGIN

-- function body

EXCEPTION

-- 例外处理

END [function_name];

(4).包(Package)

Package header:

CREATE OR REPLACE PACKAGE Package_name IS/AS

PROCEDURE procedure_name(x IN NUMBER,y OUT VARCHAR2);

FUNCTION function_name RETURN VARCHAR2;

var VARCHAR2(100);

END;

Package Body:

CREATE OR REPLACE PACKAGE BODY Package_name IS/AS

PROCEDURE procedure_name(x IN NUMBER , y OUT VARCHAR2) AS

BEGIN

IF X > 100 THEN

Y := 'X>100';

ELSE

Y := 'X<=100';

END IF;

END;

FUNCTION function_name RETURN VARCHAR2 AS

BEGIN

VAR := 'HELLO';

RETURN VAR||'EVERYONE';

END;

END;

(5).触发器(Trigger)

CREATE OR REPLACE TRIGGER trigger_name

[BEFORE | AFTER] [INSERT | UPDATE (of)| DELETE | DDL event]

ON [table | database | schema]

FOR EACH ROW

[WHEN (condition)]

DECLARE

-- 变量定义

BEGIN

-- :old.column_name

-- :new.column_name

-- if inserting then ...

EXCEPTION

END trigger_name;

只能通过触发事件来运行触发器.

DML触发器: INSERT、UPDATE、DELETE.

DDL触发器: CREATE、ALTER、DROP、TRUNCATE

数据库操作: SERVERERROR、LOGON、LOGOFF、STARTUP、SHUTDOWN

暂停: SUSPEND -- alter system suspend; alter system resume;

触发器级别: 语句级别,行级(FOR EACH ROW)

触发器内不能使用事务控制语句: Commit,Rollback,Savepoint,触发器主体调用的存储过程或函数中不能使用事务控制语句.

触发器主体可以使用: :NEW, :OLD

WHEN字句: 仅能用于行级触发器，触发器主体仅对满足WHEN字句指定条件的行进行处理.

触发器谓词: INSERTING,UPDATING,DELETING 值为TRUE/FALSE.