How to Calculate Counts from Multiple Tables in MySQL Using Left Join?
- Barbara StreisandOriginal
- 2024-10-27 02:29:30776browse
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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