Does metabase support union column name

such as ,column a_column ,column b_column ,union two column ,then give the new column a name c_column,
can metabase do this? can metabase do this in secondary develpment.?
a_column |b_column
2323 | 1212

You can do it with a custom query. Personally, I prefer to use a view, but plenty of people prefer the custom queries.