Question

我正在尝试创建一个触发器，如果客户总数达到10，那么它将引发错误

这是我的plsql代码：

    SQL> CREATE OR REPLACE TRIGGER customer_count_check
  2  BEFORE INSERT OR UPDATE ON customer2
  3  FOR EACH ROW
  4  DECLARE
  5  count_customer NUMBER(5);
  6  BEGIN
  7  SELECT COUNT(*) INTO count_customer FROM customer2
  8           WHERE cusid = :new.cusid;
  9  IF count_customer > 10 THEN
 10   Raise_application_error(-20000,'Maximum customer count:' ||
 11               count_customer || 'reached');
 12  ENDIF;
 13  END;
 14  /

这是我得到的警告：

Warning: Trigger created with compilation errors.

SQL> SHOW ERROR; 
Errors for TRIGGER CUSTOMER_COUNT_CHECK:

LINE/COL ERROR
-------- ----------------------------------------------------------------- 
10/4     PLS-00103: Encountered the symbol ";" when expecting one of the
         following:
         if

Answer 1

我有时也希望错误消息会更清楚。

第12行：

错

ENDIF;

右：

END IF;

行计数有时也不太直观。它表示为10/4，而似乎为12/4。但是前2行不被视为触发器代码的一部分，因此计数是第10行第4列。

Answer 2

SQL> CREATE OR REPLACE TRIGGER customer_count_check
  2  BEFORE INSERT OR UPDATE ON customer2
  3  FOR EACH ROW
  4  DECLARE
  5  count_customer NUMBER(5);
  6  BEGIN
  7  SELECT COUNT(*) INTO count_customer FROM customer2
  8           WHERE cusid = :new.cusid;
  9  IF count_customer > 10 THEN
 10   Raise_application_error(-20000,'Maximum customer count:' ||
 11               count_customer || 'reached');
 12  END IF;
 13  END;
 14  /

如何解决警告：触发器因编译错误而创建

2 个答案: