Question

我的问题是：

触发器，自动存储在名为“ExcellentSale”的单独表中的销售代理名称，汽车型号和制造商名称，每次商定的价格 SalesTransaction超过汽车要价的20％。（注意：你需要创建实现此触发器之前的'ExcellentSale'表。要创建主键，请使用从1开始并以1）递增的序列。

我正在使用这些表

Manufacturer(manufacturerID, name, region)

Model(modelNo, name, type, previousModel, manufacturerID)

Car(VIN, dateAcquired, yearBuilt, purchasedPrice, askingPrice,
currentMileage, modelNo)

SalesAgent(agentID, name, DOB)

SalesTransaction(VIN, custID, agentID, dateOfSale, agreedPrice)

这是我的尝试

create sequence ggenerateKey
start with 1
increment by 1;
CREATE TABLE ExcellentSale(
recordNo NUMBER,
agentName VARCHAR2(20) NOT NULL,
modelName VARCHAR2(20) NOT NULL,
manufacturerName VARCHAR2(20) NOT NULL,
PRIMARY KEY(recordNo));
create or replace trigger AutoStore
before insert on SalesTransaction
for each row
declare
agentName varchar2(50);
modelName varchar2(50);
manufacturerName varchar2(50);
askingprice number;
agreedprice number;
begin
select sa.name, mo.name, mu.name, c.askingprice, st.agreedprice
into agentName, modelName, manufacturerName, askingprice, agreedprice
from manufacturer MU, Model MO, Car C, SalesAgent SA, SalesTransaction ST
where mu.manufacturerid = mo.manufacturerid
and st.vin = c.vin
AND c.vin = :new.vin
AND sa.agentID = :new.agentID;
IF :new.agreedPrice > (1.2 * askingPrice) THEN 
INSERT INTO ExcellentSale
VALUES
(ggenerateKey.nextval, agentName, modelName, manufacturerName);
END IF; 
end AutoStore;
/

触发器编译，当我尝试测试时，我使用这些将插入SalesTransaction的值，然后应该触发触发器，但显示为错误。

insert into SalesTransaction
values
('2B7JB33R9CK683376', '1', '1', to_date('01-02-2013','dd-mm-yyyy'), 586000 );

显示的错误是

insert into SalesTransaction
            *
ERROR at line 1:
ORA-01403: no data found 
ORA-06512: at "JTLA.AUTOSTORE", line 8 
ORA-04088: error during execution of trigger 'JTLA.AUTOSTORE'

Answer 1

此错误表示您的select语句带有＆＃34; into＆＃34;子句不产生任何行。为了避免这个错误，我通常在每一列上使用聚合函数MAX（），它使用1行结果集，在没有匹配行的情况下生成空值，并且没有异常上升

问题使用Oracle创建触发器

1 个答案: