sebastien61
21st July 2009 08:48 UTC

Detecting all previous postgres install
Hi everybody,

This is the first time I post in NSIS forum so please forgive my ignorance ;)

I have to detect if postgreSQL is already installed on a computer. I searched on the web and read many things doing this, but they did not help me.

Do I have to check in the registry if there is a SOFTWARE\PostgreSQL\... key in the registry or if a service is present ? What is the best solution ?

The solution I choose is the 2nd one (it may not be the right one...). I use 'Services' plugin for NSIS. But problem is that there are several versions of postgreSQL, so do I have to try every version of them with :
services::IsServiceInstalled 'postgresql-8.3'
services::IsServiceInstalled 'postgresql-8.2'
services::IsServiceInstalled 'postgresql-8.1'...

?

Thank you in advance for help/advices.

jpderuiter
21st July 2009 17:04 UTC

Yes, you have to try all of them, so I think that is not the best approach.
I think the best would be to get it from the registry.
Have a look here for an idea:
http://forums.winamp.com/showthread....hreadid=278622

sebastien61
24th July 2009 11:10 UTC

Hi jpderuiter !

Thank you so much, thanks to you I found how to do that. For people who still search, I proceed like that :

 
services::GetServiceNameFromDisplayName 'postgre' 
Pop $0 IntCmp $0 0 NotInstalledYet ; if research returned "0" No previous install has been found 
IntOp $0 $0 - 1 Pop $1 ; If already installed, we collect the install location in the registry 
ReadRegStr $R0 HKLM "SOFTWARE\\PostgreSQL\\Installations\\$1" "Base Directory"

NotInstalledYet :
  ; install postgres...