如何使用数据库中的另一个表更新表记录？

Question

Table one: products Which have fields like

products_id
products_price
master_categories_id

Table two: specials . This table is empty,Fields in it are

specials_id (an  autoincrement field)
products_id (the value same as table one)
specials_new_products_price (the value equals products_price-(products_price*0.05))
specials_date_added (the value like this 2011-12-05 12:17:44)
specials_last_modified (the value like this  2011-12-05 12:19:10)
expires_date  (2011-12-31)
date_status_change  (the value like this 2011-12-05 12:19:10)
status  (1) 
specials_date_available  (2011-11-29)

now, i want to insert the data

("SELECT products_id,products_price FROM products where master_categories_id=79")
into table 2. and set the `status=1, specials_date_available=2011-11-29, 
expires_date=2011-12-31`.`products_id(the value same as table one)

specials_new_products_price (the value equals products_price-(products_price*0.05)) 

the rest field's value is up to you.

the way that i think which is not good ,write a php file to do the insert. select out the products_id,products_price , then put them in a txt file one line after another, then put the file content into the table 2. but i don't know how to put the text file data into the table2 and how to set the rest fields value?

Answer 1

insert into specials
(products_id, products_price,status,specials_date_available,expires_date)
SELECT products_id,products_price*0.95 as products_price,
 1, '2011-11-29', '2011-12-31'
FROM products where master_categories_id=79

or something like that.