MySQL Edit Syntax

I have a table called 'charges'

I want to update the value of field 'calculated_weight' based on the contents of 'department_id', which will determine what to multiply against 'quantity' to determine the update value for 'calculated_weight'.  Example:

UPDATE `charges` SET `calculated_weight` = IF(`department_id` IS 4120, 1, 2);

Now, that isn't want I want, but puts into logical form the paragraph above it *almost.  

What I really want is to insert (quantity*.0857) into `calculated_weight` when `department_id` == 4120.
IF
'department_id' == 4250, then i would want (quantity*1.0147) to insert into 'calculated_weight'

I have about 6 departmentIDs to monitor and adjust the mutlplication value for.  

I tried a few options in MySQL, but it isn't working out for me.  

Thanks
weklicaAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

GaryCommented:
Why not this for each department and repeat just adjusting the calculation

UPDATE `charges` SET `calculated_weight` = (quantity*.0857) where department_id=4120

edited
For multiple departments then just an OR

UPDATE `charges` SET `calculated_weight` = (quantity*.0857) where department_id=4120 OR department_id=4121 OR department_id=4122
AshokSr. Software EngineerCommented:
Try

UPDATE `charges` SET
`calculated_weight` =
CASE `department_id` WHEN 4120 THEN quantity*.0857
WHEN `department_id` WHEN 4250 THEN quantity*1.0147
....
ELSE 'Charges' END

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
NorieAnalyst Assistant Commented:
Have you tried using CASE..WHEN?

UPDATE `charges`
SET `calculated_weight` =
  CASE
     WHEN `department_id`= 4120 THEN quantity*0.0857
     WHEN `deparment_id` = 4250 THEN quantity*1.0147
      -- etc
  END
Exploring ASP.NET Core: Fundamentals

Learn to build web apps and services, IoT apps, and mobile backends by covering the fundamentals of ASP.NET Core and  exploring the core foundations for app libraries.

weklicaAuthor Commented:
That works perfectly.  I thought I tried something like that, but clearly missed something.  I used this specifically and it worked:

UPDATE  `charges` SET  `calculated_weight` = (  `quantity` * .0857 ) WHERE  `department_id` =4120
weklicaAuthor Commented:
I just noticed the CASE when option and will ultimately go wtih that one.  Very much appreciated.  You guys are awesome.
GaryCommented:
I did a small edit for doing multiple departments.
NorieAnalyst Assistant Commented:
cathal

If you have multiple deparments why not use an IN clause.

`deparment_id` IN (4120, 4121, 4122)
AshokSr. Software EngineerCommented:
I have about 6 departmentIDs to monitor and adjust the mutlplication value for.  

If you are going to update all 6 departments (the whole table), you do not need

where `deparment_id` IN (4120, 4121, 4122)
GaryCommented:
Cos I was having a dumb blonde moment.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Apache Web Server

From novice to tech pro — start learning today.