[ILUG] PostgreSQL vs. MySQL

[Nick Murtagh]

Ronan Waide wrote:
> UI:
>   try {
>     store in Database
>   } catch {
>     burp loudly
>   }
> 
> Database:
>   if ( values are ok )
>     throw exception
>   else
>     insert values

I have a problem with this design - and it's mainly to do with the burp
loudly part. If some intermediate layer or the application itself does
validation, you can have the GUI give an error message explaining
what went wrong and what to do about it. If the database "throws an 
exception", you have two choices. One, display the error message 
returned by the db, probably something along the lines of "Constraint 
violated ..." which won't mean anything to the average end user. Or try 
and parse the error messages from the database and report something 
sensible to the user.

You're always going to need to do some validation directly in the GUI,
unless you want a really unusable GUI.

Nick