在PL/SQL触发器中使用Select语句的语法是什么？

Question

这就是我目前拥有的:

CREATE OR REPLACE TRIGGER MYTRIGGER
AFTER INSERT ON SOMETABLE
FOR EACH ROW    

DECLARE
 v_emplid varchar2(10);    

BEGIN
 SELECT
  personnum into v_emplid
 FROM PERSON
 WHERE PERSONID = :new.EMPLOYEEID;

dbms_output.put(v_emplid);

/* INSERT INTO SOMEOTHERTABLE USING v_emplid and some of the other values from the trigger table*/

END MYTRIGGER;    

DBA_ERRORS有此错误:PL/SQL:ORA-00923:未找到FROM关键字

Answer 1

1)你的例子必须有其他东西,因为这肯定对我有用

SQL> create table someTable( employeeid number );

Table created.

SQL> create table person( personid number, personnum varchar2(10) );

Table created.

SQL> ed
Wrote file afiedt.buf

  1  CREATE OR REPLACE TRIGGER MYTRIGGER
  2    AFTER INSERT ON SOMETABLE
  3    FOR EACH ROW
  4  DECLARE
  5   v_emplid varchar2(10);
  6  BEGIN
  7   SELECT personnum
  8     into v_emplid
  9     FROM PERSON
 10    WHERE PERSONID = :new.EMPLOYEEID;
 11    dbms_output.put(v_emplid);
 12    /* INSERT INTO SOMEOTHERTABLE USING v_emplid and some of the other values
 from the trigger table*/
 13* END MYTRIGGER;
 14  /

Trigger created.

SQL> insert into person values( 1, '123' );

1 row created.

SQL> insert into sometable values( 1 );

1 row created.

2)您可能希望将V_EMPLID声明为Person.PersonNum%TYPE类型,以便您可以确定数据类型是正确的,这样如果表的数据类型发生更改,您将无需更改代码.

3)我假设您知道您的触发器无法查询或更新定义了触发器的表(因此不会对someTable进行查询或插入).