Understanding Multiple Table Join within a single database
Often there will be instances where the data is stored in multiples tables of a database and for the sake of analysis, we are required to fetch the data from these tables.
For example, there may be a table called Employee Master which contains the employee details such as employee ID, their first name, last name, date of birth and so on. The salary/compensation details could be stored in another table and the employment history could be stored in a separate table as well.
When conducting an analysis, we would want to consider all the information related to an employee and then proceed with our analysis. Thus, in this case, we are required to fetch the data from all the three tables, and while doing so we will also have to specify the Joins by defining a primary key. The primary key in this case could be Employee ID which is common across all the tables.
The functionality is called Multiple Table Joins and it is used when we want to...