<http://i.stack.imgur.com/ZRH9c.jpg> (Please see Example Image of Database Structure)

Hi all,

I'm trying to search for words in two tables that Start with a specific Letter and I don't know how to do the proper join.

**If there is NOT given a voc\_id in "user\_vocabulary" I want to take the word from user\_vocabulary but if there is a voc\_id I want to read all data from "system\_vocabulary" WHERE user\_vocabulary.voc\_id=system.vocabulary.id .**

This I use to just read one table (just for your information):
 SELECT \* FROM user\_vocabulary WHERE word LIKE '$user\_input%' ORDER BY word ASC 

I've found some more or less similar posts but seem not to be able to convert those to this issue.

Any help is much appreciated.
cheers
Tom