How to Calculate Counts from Multiple Tables in MySQL Using Left Join?

Using Left Join to Calculate Counts from Multiple Tables in MySQL

In order to add columns representing counts from other tables, a left join can be utilized. For instance, consider the following tables:

Messages

MessageID	User	Message	Topic
1	Tom	Hi	ball
2	John	Hey	book
3	Mike	Sup	book
4	Mike	Ok	book

Topics

| Topic |

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