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Question
Explain the meaning of the term 'Join' as a tool of SQL.
Solution
An SQL Join is an operation that combines records from two or more tables. This is done by matching keys between tables. It comes in handy when we want to correlate a lot of information stored in multiple tables to make more sense of the information or to answer core business questions in any sort of enterprise environment.
To start a join process, first, we need to identify tables that share keys since this is the only way we can combine information in a way that makes sense. When joining tables, you can only join on keys, but you can join a primary key to either another primary key or a foreign key. If tables don't have keys in common, the join can be performed but it will just combine the information without any sort of purpose.
