AFTERUPDATEONtable_nameDECLARExx; PRAGMA AUTONOMOUS_TRANSACTION;BEGINxx;COMMIT;END; PRAGMA AUTONOMOUS_TRANSACTION; 和 COMMMIT; 语句是必须的。 代替触发器(INSTEAD OF 触发器) 代替触发器定义于视图 CREATEORREPLACEtrigger_name INSTEADOFDELETEONtable_nameBEGINxxxx;END; 假如在一个视图上进行删除操作,但是有完...
Example 9-13 Trigger Derives New Column Values(触发器派生新列值) Example 9-2 INSTEAD OF Trigger Example 12-10 FORALL Statement for Subset of Collection(集合的子集) Bulk-Selecting into Nested Table of Records(批量选择嵌套记录表) ...
Example:要求员工涨工资后,不能低于原来的工资,所涨工资也不能高于原来的50%。 这里为了不改变oracle中emp表的数据,新建一个emp_new表 createtableemp_newasselect*fromemp; CREATEORREPLACETRIGGERemp_trigger BEFOREUPDATEOFsalONemp_newFOREACH ROWWHEN(new.sal<old.salORnew.sal>1.5*old.sal)BEGINRAISE_APPLICATI...
create table emp_new as select * from emp;create table dept_new as select * from dept;CREATE OR REPLACE TRIGGER cascade_trigger AFTER UPDATE OF deptno ON dept_new FOR EACH ROW BEGIN UPDATE emp_new SET deptno=:new.deptno WHERE deptno=:old.deptno; END;update dept_new set deptno=15 where...
触发器的意思就是当我们对数据库对象(一般是表或视图)进行insert、update、delete操作的时候,这些操作会相应的触发一些事件的执行,通常要执行的事件被写成PL/SQL程序,那么这些数据库对象上的事件相关的程序就是触发器(trigger)。Oracle数据库中,触发器分为before、after、instead of三种,其中before、after主要对于表操作...
Example Consider the following rather selfish trigger. I have created a view called best_sellers that sits on top of the book table. When you insert a row into best_sellers, it actually inserts a row only if the publisher of the book is O’Reilly & Associates!
Row-level triggers are emulated using cursors. Compound triggers are converted to INSTEAD OF triggers. Multiple compound triggers are combined into single trigger Cascading triggers are converted into multiple individual triggers. SynonymsSynonyms are created for the following object types: ...
By default, the Migration Workbench uses the temporary tables feature of Oracle9i. When the parser encounters SQL statements such asCREATE #TABLEin a stored procedure, the parser explicitly creates a temporary table. When the parser encounters SQL statements such asINSERT INTO #TABLEin a trigger or...
TIMESTAMP columns are migrated by creating a NUMBER column on which an UPDATE/INSERT trigger is defined. A SEQUENCE is also defined from which the trigger retrieves the next value whenever it fires. MS SQL Server and Sybase Data Types
This can be used with the most of export types: TABLE, TRIGGER, PROCEDURE, VIEW, FUNCTION or PACKAGE, etc. ORA_INITIAL_COMMAND This directive can be used to send an initial command to Oracle, just after the connection. For example to unlock a policy before reading objects or to set some...