涉及多个表的触发器Oracle、PL/SQL

我是SQL新手，我正在尝试找出触发器。我需要编写一个涉及3个表的触发器，不要担心它只由其中一个表触发

CREATE TABLE CUSTOMERS 
(CUSTID CHAR(8) constraint customers_pk primary key, 
CREDITSCORE NUMBER(5,2)

CREATE TABLE LOANDETAILS 
(LOANNO VARCHAR2(11) primary key, 
CUSTID CHAR(8),  
LOANSTATUSCODE NUMBER(3,0), 
RATE NUMBER(5,2), 

CREATE TABLE SCORECONVERSIONCHART 
(SCOREBAND VARCHAR2(1) constraint scorecc_pk primary key, 
MINSCORE NUMBER(3,0), 
MAXSCORE NUMBER(3,0), 
BASERATEADJUSTMENT NUMBER(4,2)
);

因此，当更新customer表中的信用评分（creditscore）时，我想查看loan details表中的贷款类型（LoantType）。如果贷款类型是1或2，我想更新贷款明细表中的贷款利率。通过查看分数转换图表表中自定义信用分数的下降位置（客户表中的creditscore）更新贷款利率-如果它在转换图表表中的给定最低和最高分数之间，则相应的基准利率调整将添加到3%的基准利率

我不清楚如何让所有这些表在触发器中交互

---

如果有人能用通俗易懂的语言帮助我或给我指出一个很好的资源，我将不胜感激。

下面的例子可能会为您提供一个起点。
如果贷款类型为可调整类型，则只有在信用评分更新时，此触发器才会通过

SCORECONVERSIONCHART

中的转换有条件地更新贷款详细信息

首先，添加一些测试数据：

INSERT INTO CUSTOMERS VALUES ('00000000','Frodo','Baggins',null,null,null,'frodo@hobbiton.com',123,750);
INSERT INTO CUSTOMERS VALUES ('00000001','Chewbacca','?',null,null,null,'chewie@hoth.com',456,775);


INSERT INTO LOANDETAILS VALUES ('A',NULL,'00000000','1',NULL,NULL,7.2,NULL,NULL);
INSERT INTO LOANDETAILS VALUES ('B',NULL,'00000001','3',NULL,NULL,4.2,NULL,NULL);

INSERT INTO SCORECONVERSIONCHART VALUES ('X',500,599,22);
INSERT INTO SCORECONVERSIONCHART VALUES ('Y',600,699,3);
INSERT INTO SCORECONVERSIONCHART VALUES ('Z',700,799,1);
COMMIT;

然后创建

触发器

编辑原始示例，假设每个客户只有一笔贷款。更新以处理每个客户的多笔贷款

CREATE OR REPLACE TRIGGER Q2
AFTER UPDATE OF CREDITSCORE
  ON CUSTOMERS
FOR EACH ROW
  DECLARE
    V_LOAN_TYPE NUMBER;
  BEGIN
      UPDATE LOANDETAILS
      SET RATE = (SELECT SCORECONVERSIONCHART.BASERATEADJUSTMENT + 3
                  FROM SCORECONVERSIONCHART
                  WHERE :NEW.CREDITSCORE BETWEEN SCORECONVERSIONCHART.MINSCORE
                  AND SCORECONVERSIONCHART.MAXSCORE)
      WHERE LOANDETAILS.CUSTID = :NEW.CUSTID
      AND LOANDETAILS.LOANTYPE IN ('1','2');
END;
/

然后，测试它：

SELECT CUSTID, LOANTYPE, RATE FROM LOANDETAILS;
CUSTID    LOANTYPE  RATE  
00000000  1         7.2   
00000001  3         4.2   

然后，更新非信用评分属性：

UPDATE CUSTOMERS SET STATE = 'WI';
SELECT CUSTID, LOANTYPE, RATE FROM LOANDETAILS;
CUSTID    LOANTYPE  RATE  
00000000  1         7.2   
00000001  3         4.2   

然后更新信用评分。佛罗多的贷款变化（他的贷款类型符合条件）为3%+分数转换哈特调整3%，但丘伊的贷款根本没有变化

UPDATE CUSTOMERS SET CREDITSCORE = 600;
SELECT CUSTID, LOANTYPE, RATE FROM LOANDETAILS;
CUSTID    LOANTYPE  RATE  
00000000  1         6     
00000001  3         4.2   

---

如果贷款类型是数字，我建议将其记录为数字。

以下示例可能为您提供一个起点。
如果贷款类型为可调整类型，则只有在信用评分更新时，此触发器才会通过

SCORECONVERSIONCHART

中的转换有条件地更新贷款详细信息

首先，添加一些测试数据：

INSERT INTO CUSTOMERS VALUES ('00000000','Frodo','Baggins',null,null,null,'frodo@hobbiton.com',123,750);
INSERT INTO CUSTOMERS VALUES ('00000001','Chewbacca','?',null,null,null,'chewie@hoth.com',456,775);


INSERT INTO LOANDETAILS VALUES ('A',NULL,'00000000','1',NULL,NULL,7.2,NULL,NULL);
INSERT INTO LOANDETAILS VALUES ('B',NULL,'00000001','3',NULL,NULL,4.2,NULL,NULL);

INSERT INTO SCORECONVERSIONCHART VALUES ('X',500,599,22);
INSERT INTO SCORECONVERSIONCHART VALUES ('Y',600,699,3);
INSERT INTO SCORECONVERSIONCHART VALUES ('Z',700,799,1);
COMMIT;

然后创建

触发器

编辑原始示例，假设每个客户只有一笔贷款。更新以处理每个客户的多笔贷款

CREATE OR REPLACE TRIGGER Q2
AFTER UPDATE OF CREDITSCORE
  ON CUSTOMERS
FOR EACH ROW
  DECLARE
    V_LOAN_TYPE NUMBER;
  BEGIN
      UPDATE LOANDETAILS
      SET RATE = (SELECT SCORECONVERSIONCHART.BASERATEADJUSTMENT + 3
                  FROM SCORECONVERSIONCHART
                  WHERE :NEW.CREDITSCORE BETWEEN SCORECONVERSIONCHART.MINSCORE
                  AND SCORECONVERSIONCHART.MAXSCORE)
      WHERE LOANDETAILS.CUSTID = :NEW.CUSTID
      AND LOANDETAILS.LOANTYPE IN ('1','2');
END;
/

然后，测试它：

SELECT CUSTID, LOANTYPE, RATE FROM LOANDETAILS;
CUSTID    LOANTYPE  RATE  
00000000  1         7.2   
00000001  3         4.2   

然后，更新非信用评分属性：

UPDATE CUSTOMERS SET STATE = 'WI';
SELECT CUSTID, LOANTYPE, RATE FROM LOANDETAILS;
CUSTID    LOANTYPE  RATE  
00000000  1         7.2   
00000001  3         4.2   

然后更新信用评分。佛罗多的贷款变化（他的贷款类型符合条件）为3%+分数转换哈特调整3%，但丘伊的贷款根本没有变化

UPDATE CUSTOMERS SET CREDITSCORE = 600;
SELECT CUSTID, LOANTYPE, RATE FROM LOANDETAILS;
CUSTID    LOANTYPE  RATE  
00000000  1         6     
00000001  3         4.2   

---

如果贷款类型是数字，我建议将其记录为数字。

您可以执行以下操作

    CREATE OR REPLACE TRIGGER trig
        AFTER UPDATE OF CREDITSCORE 
        ON CUSTOMERS
        FOR EACH ROW
        DECLARE
        temp_RATE LOANDETAILS.RATE%type
        temp_adj  SCORECONVERSIONCHART.BASERATEADJUSTMENT%type;
        BEGIN
        UPDATE LOANDETAILS
        SET RATE = RATE + 0.03* ( select s.BASERATEADJUSTMENT from customer c join loandetails l on c.custid=l.custid cross join SCORECONVERSIONCHART s where new.crediscore between s.minscore and s.maxscore and l.LOANTYPE in (1,2) and c.custid=new.custid)
WHERE CUSTID= ( select c.custid from customer c join loandetails l on c.custid=l.custid cross join SCORECONVERSIONCHART s where new.crediscore between s.minscore and s.maxscore and l.LOANTYPE in (1,2) and c.custid=new.custid)

        END IF;
        END;
        /

---

现在，通过上面的子查询，u将获得符合条件的客户的基准利率。您可以根据您的要求更改费率。

您可以执行以下操作

    CREATE OR REPLACE TRIGGER trig
        AFTER UPDATE OF CREDITSCORE 
        ON CUSTOMERS
        FOR EACH ROW
        DECLARE
        temp_RATE LOANDETAILS.RATE%type
        temp_adj  SCORECONVERSIONCHART.BASERATEADJUSTMENT%type;
        BEGIN
        UPDATE LOANDETAILS
        SET RATE = RATE + 0.03* ( select s.BASERATEADJUSTMENT from customer c join loandetails l on c.custid=l.custid cross join SCORECONVERSIONCHART s where new.crediscore between s.minscore and s.maxscore and l.LOANTYPE in (1,2) and c.custid=new.custid)
WHERE CUSTID= ( select c.custid from customer c join loandetails l on c.custid=l.custid cross join SCORECONVERSIONCHART s where new.crediscore between s.minscore and s.maxscore and l.LOANTYPE in (1,2) and c.custid=new.custid)

        END IF;
        END;
        /

---

现在，通过上面的子查询，u将获得符合条件的客户的基准利率。您可以根据您的要求更改该费率。

您对上述代码有什么问题？您对上述代码有什么问题？谢谢您的全面回答，看到与设置费率相关的查询是一件很有启发性的事情。我读过的大部分文档都没有详细介绍，谢谢@Mike。如果有任何不寻常的事情发生，或者我可以澄清的事情，请让我知道。谢谢你的全面回答。作为一个noob，看到与设定利率相关的查询是很有启发性的。我读过的大部分文档都没有详细介绍，谢谢@Mike。如果有什么不寻常的事情发生，或者有什么我可以澄清的，请告诉我，谢谢你。很高兴看到另一个解决方案。我检查了另一个解决方案，因为它使用的代码更少。尽管如此，看到你的解决方案还是很有启发性的。谢谢你。很高兴看到另一个解决方案。我检查了另一个解决方案，因为它使用的代码更少。尽管如此，看到你的解决方案还是很有启发性的。