Upgraded to iPhoto 11 version 9.3 and lost all 47GB photos after prompted to update library. Can I get my photos back?

Question

The iPhoto library is still the same size in Finder. But when opening iPhoto it only shows the new photos currently from photostream and none of my albums, last 12 months, etc. Thank you for any help on this.

Answer 1

You're photos are safe in the Master's folder of your library.  The library just can't link to them.  Try the following:  make a temporary, backup copy (select the library and type Command+D) and apply the two fixes below in order as needed:
Fix #1
Launch iPhoto with the Command+Option keys held down and rebuild the library.
Select the options identified in the screenshot. 
Fix #2
Using iPhoto Library Manager  to Rebuild Your iPhoto Library
Download iPhoto Library Manager and launch.
Click on the Add Library button, navigate to your Home/Pictures folder and select your iPhoto Library folder.
Now that the library is listed in the left hand pane of iPLM, click on your library and go to the File ➙ Rebuild Library menu option
In the next  window name the new library and select the location you want it to be placed.
Click on the Create button.
Note: This creates a new library based on the LIbraryData.xml file in the library and will recover Events, Albums, keywords, titles and comments but not books, calendars or slideshows. The original library will be left untouched for further attempts at fixing the problem or in case the rebuilt library is not satisfactory.
If that fails try
Start over from scratch with new library
Start over with a new library and import the Originals (iPhoto 09 and earlier) or the Masters (iPhoto 11) folder from your original library as follows:
1. Open the library package like this.
2. Launch iPhoto with the Option key held down and, when asked, select the option to create a new library.
3. Drag the Originals (iPhoto 09 and earlier) or the Masters (iPhoto 11) folder from the open iPhoto Library package into the open iPhoto window.
Click to view full size
This will create a new library with the same Events (but not necessarily the same Event names) as the original library but will not keep the metadata, albums, books slideshows and other projects.
Note:  your current library will be left untouched for further attempts at a fix if so desired.
Of course if you have a backup copy of your library from just before the problem started that would be your best  move.
OT