Some of us while writing an SQL select statement with a join between two tables or more may get confused with whether to add a certain condition to the "ON" clause of the join or just add it to the "WHERE" clause as if it is just a filtering condition. Some people may think that both approaches will return the same results every time. This is not completely true. Yes in some cases both approaches will return the same results but in other cases they won't. If you want to know more, you can read this article.