Tableau – Join databases

Designing good data has a fundamental principle of spreading the data out so that each data table stores the information about a particular business entity.
Let’s suppose that the model has a set of restaurants which are located in different cities. Each of these restaurants could have a restaurant ID, the restaurant city and the restaurant state. Another table has a list of workers for the entire restaurant chain with a field indicating which restaurant they are working at. So it is possible to link these two tables based on the common data attribute or field of restaurant ID (in this case).
This article aims to explain the principle of creating a connection between related data with the data source in Tableau.

Steps to perform:

• In the Tableau, connect to the databases.
• The data source has three data files – Product, OrderDetails, PropertyInfo. These are three different excel sheet present in one data file.
  
• Open Product data file.
  
• Add OrderDetails data file, it contains the information about each order.
  
• Now you can see there is a join in the two data files.
  
• If you’ll hover on the join then you can see that there is a inner join using the common key i.e. Product ID. Inner join simply means that there are two files have a field in common and it can be combined easily.
• Next, add the PropertyInfo file and it can be see that it is also joined.
  
• If you’ll hover the mouse pointer then it can be clearly seen that OrderDetails and PropertyInfo are inner joined using the key – PropertyID.
  
• Now, that data is completely ready for data visualisation.