SQLite Forum

How to select entries from second table that either do not have an entry or do not have a specific entry?

I'm trying to find entries in that either 
- do not have an entry at all
- or do not have a specific entry

Example:

TABLE 1
Field A
100
101
102

TABLE 2
Field A.         Field B
100                X
100.               Y
100.               Z
101.                Y
101                 Z


The result should be:
101
102

Thanks a lot already!!!