Tricky SQL update

[David FOXWELL <David.FOXWELL@xxxxxxxxx>]

Hi everyone,

I have a PF, as a result of an extraction, like this :

Client    ProductType     Profession
C1        PT1                    Doctor
C1        PT2                    Lawyer
C2        PT2                    Binman

I want to modify the profession like this :

Client    ProductType     Profession
C1        PT1                    Doctor
C1        PT2                    Doctor
C2        PT2

In the example, the profession must come from PT1 only. If the client doesn't have PT1, his profession is erased. If he has another product as well as PT1 the profession of that product is that recorded for PT1.

Is there an SQL instruction to update the profession in this way ?  I think it must be possible but doubt that it would be human readable!

Thanks