Updating a date field witha field from another table

Question

Hi friends
I have a table called Customer_Type with following fields
Customer_type ,Active_date, Inactive_date
regular,11/01/2011
daily,11/04/2011
monthly,11/05/2011/11/11/2011
Tbale 2:Customer
Customer_name,Customer_type,Customer_Inactive_date
John,regular,
James,monthly,
Jake,daily,
Jill,monthly
What i wnat is to update the Customer_inactive_date with the Incative_date field from Customer_type
based on their Customer_type... So james and Jill would have their rows updated in this scneario ..How can i achive this in pl/Sql
Thank you in advance...

Answer 1

Hi,
You can look at this code; it's not PL/SQL but a simple MERGE statement:
CREATE TABLE CUSTOMER_TYPE
  type_code VARCHAR2(10),
  active_date DATE,
  inactive_date DATE
INSERT INTO customer_type VALUES('REGULAR', TO_DATE('11/01/2011', 'DD/MM/YYYY'), null);
INSERT INTO customer_type VALUES('DAILY', TO_DATE('11/04/2011', 'DD/MM/YYYY'), null);
INSERT INTO customer_type VALUES('MONTHLY', TO_DATE('11/05/2011', 'DD/MM/YYYY'), TO_DATE('11/11/2011', 'DD/MM/YYYY'));
CREATE TABLE CUSTOMERS
  customer_name varchar2(10),
  customer_type varchar2(10),
  customer_inactive_date DATE
INSERT INTO customers VALUES('John', 'REGULAR', null);
INSERT INTO customers VALUES('James', 'MONTHLY', null);
INSERT INTO customers VALUES('Jake', 'DAILY', null);
INSERT INTO customers VALUES('Jill', 'MONTHLY', null);
MERGE INTO customers dst
USING customer_type src
ON (dst.customer_type = src.type_code)
WHEN MATCHED THEN
  UPDATE set dst.customer_inactive_date = src.inactive_date;
SELECT * FROM customers;
CUSTOMER_NAME CUSTOMER_TYPE CUSTOMER_INACTIVE_DATE   
John          REGULAR                                
James         MONTHLY       11-NOV-11                
Jake          DAILY                                  
Jill          MONTHLY       11-NOV-11                 If you don't understand it, just let me know...