How can I update a column based on multiple values from multiple columns

Question

I am new to this. I want to update a column value where based on values of other columns. Example

Product   Make     Model         Years
Hyundai   Getz     1.4 Hatch/3D     5
Hyundai   Getz     1.4 Hatch/5D     5
Hyundai   Getz     1.6 Hatch/5D     7
Hyundai   Getz     1.6 Hatch/5D     7

I tried the following

UPDATE WARRANTY
SET  WARRANTY.period = 
    Case when PRODUCT.grpcode ='Hyundai'  
         and PRODUCT.Make =’Getz’  
         and PRODUCT.Model in ('1.4 Hatch/3D',1.4 Hatch/5D')
then 5
 end 
 end

Is this right?

Answer 1

So depending on which SQL you are working on, the approach will change. Here's one way to approach this:

update warranty
set period = case  when PRODUCT.grpcode ='Hyundai'  
     and PRODUCT.Make ='Getz'  
     and PRODUCT.Model in ('1.4 Hatch/3D','1.4 Hatch/5D')
then 5
from product
where product.pid = warranty.pid

you will need a column in order to join the 2 tables. I am assuming you would have a column like that. This is an example of postgresql for Mysql you can do something like this:

UPDATE warranty
    INNER JOIN
product ON product.pid = warranty.pid 
SET 
period = case  when PRODUCT.grpcode ='Hyundai'  
     and PRODUCT.Make ='Getz'  
     and PRODUCT.Model in ('1.4 Hatch/3D','1.4 Hatch/5D')
then 5

you will have to do this for all the products and manually change values for all the products and run the code multiple times.