Combining Multiple Tables

[Tim Carty]

I would like to combine multiple tables into a single table. I can create a
UNION between tables with similar columns ­ cols A, B, and C  from table_1
with cols A, B, and C from Table_2. What I can¹t figure out is how to add
additionals columns (D, E, F) from table_2 if the columns don¹t exist in
Table_1.