Excellent. Here is another keyword:
INTERSECT. Let's change our example a little bit:
WHERE country = 'Germany'
WHERE country = 'Germany';
UNION ALL), we've put
INTERSECT in there. What's the difference?
UNION gave you all the results from the first query PLUS the results from the second query.
INTERSECT, on the other hand, only shows the rows which belong to BOTH tables.
In this case, we would get the years when Germany got a medal in cycling AND speed skating at the same time.
The conditions here stay the same: the number of columns in both tables must be the same and the number or text values must match.