Data joining is a common requirement in any data analysis. You may need to join data from different tables in a single source or join data from multiple sources.
Tableau provides the feature to join the tables by using the data pane that is available in the Data menu.
A join means combining columns from one or more tables in a relational database. It also creates a set that can be saved as a table, or it can be used as it is.
Joins are specifies into five types:
1. Cross Join.
2. Inner Join.
3. Natural Join.
4. Outer Join.
i. Left Outer Join.
ii. Right Outer Join.
iii. Full Outer Join.
5. Self-Join.

Overview of Types of Joins

A join section is used to combine rows from two or more tables, based on a related column between them.
1. Cross Join: Cross join produces rows which combine each row from the first table with each row from the second table.

2. Inner Join: An inner join returns the matching rows from the tables that are being joined.

3. Natural Join: Natural join is not used any comparison operator. It does not concatenate the way.
Only we can perform a Natural Join if there is at least one common attribute that exists between two relations. Also, the attributes must have the same name and domain.
Natural join works on those matching attributes where the values of attributes in both the relation are same.
4. Outer Join: An outer join is an extended form of the inner join.
It returns both matching and non-matching rows for the tables that are being joined.
Types of outer joins are as follows:
i) Left Outer Join: The left outer join returns matching rows from the tables being joined, and also non-matching rows from the left table in the result and places NULL values in the attributes that come from the right table.

ii. Right Outer Join: The right outer join operation returns matching rows from the tables being joined, and also non-matching rows from the right table in the result and places NULL values in the attributes that come from the left table.

iii. Full Outer Join: The full outer join is used to combine tables. As a result, it contains all values from both tables.
When a value from a table doesn’t have a match with the other table, then it returns a NULL value in the data grid.

5. Self-Join: The self-join is used to join a table with itself. It means that each row of the table is combined with itself as well as with every other row of the table.

Creating a Join in Tableau

Let’s assume a data source Sample-superstore to create a join between two tables such as Orders and Returns.
• Go to the Data menu and choose Microsoft Excel option below connect.
• Then select sample-superstore as a data source and click the Open button.
• Drag Orders and Returns tables from sheets of the data source to the data pane. After that Tableau will automatically create a join between Orders and Returns tables which can be changed later as per required joins.

• Below screenshot shows the building inner join between Orders and Returns tables by using the Order id field.

Edit a Join Type in Tableau

Tableau automatically creates a type of join between two tables, but it can be changed as per need.
• Click on the middle of two circles that showing the auto-created join.
• After clicking, a popup window appears which shows all the four types of the joins.
• In below screenshot, you can see all the joins such as inner join, left outer join, right outer join, and full outer join.

How to Edit Join Fields in Tableau

• Also, you can change the fields by clicking the Data Sources option to add a new join clause that is available in the join popup window.
• While selecting the field, you can search for the field using a search text box.

So, this brings us to the end of blog. This Tecklearn ‘How to Join Data in Tableau using multiple sources’ blog helps you with commonly asked questions if you are looking out for a job in Tableau Desktop. If you wish to learn Tableau Desktop and build a career in Business Intelligence domain, then check out our interactive, Tableau Desktop Training, that comes with 24*7 support to guide you throughout your learning period. Please find the link for course details:

Tableau Desktop

Tableau Desktop Training

About the Course

Tecklearn’s Tableau Desktop Training teach you how to transform raw data into interactive and shareable dashboards using Tableau. Our Tableau Course covers the necessary analytical skills to Advanced data visualizations by incorporating real-world use-case scenarios, labs, and exercises. Some of the topics included are Data Blending, Data Mapping, Graphs, creation of charts, and LOD expression by using different versions of Tableau, such as Tableau Desktop, Tableau Reader, and Tableau Public.

Why Should you take Tableau Desktop Training?

• The average salary of a Tableau Professional ranges between $108,697 to $158,000 per annum -Indeed.com.
• Tableau has been positioned as a Leader in the Gartner Magic Quadrant for Analytics and Business Intelligence Platforms – Gartner.com.
• Fidelity Investments, Capgemini, EY, Deloitte, EY, JP Morgan, Verizon, Facebook, Dell, General Motors, KPMG, Bank of America and 40,000 other MNCs worldwide across industries use Tableau.

What you will Learn in this Course?

Understanding Tableau

• Why Tableau
• Tableau Product Platforms
• Tableau Architecture
• Tableau Interface

Data Connection with Tableau Desktop

• Features of Tableau Desktop
• Connect to data from File and Database
• Types of Connections
• Data Blending
• Joins and Unions
• Tableau Desktop User Interface
• Basic project: Create a workbook and publish it on Tableau Online

Basic Visual Analytics

• Visual Analytics
• Basic Charts: Bar Chart, Line Chart, and Pie Chart
• Hierarchies
• Data Granularity
• Highlighting
• Sorting
• Filtering
• Grouping
• Sets

Advanced Visual Analytics

• Parameters
• Tool tips
• Trend lines
• Reference lines
• Forecasting
• Clustering

Calculations in Tableau

• Calculated Fields
• Numeric, String, Data, Logical, Addressing and Partitioning
• Table Calculations

Level of Detail (LOD’s) Calculations

Advanced Charts in Tableau

• Box and Whisker’s Plot
• Bullet Chart
• Bar in Bar Chart
• Gantt Chart
• Waterfall Chart
• Pareto Chart
• Control Chart
• Funnel Chart
• Bump Chart

Parameters

• What If Scenarios
• Parameter in CF (KPI control)
• Parameter in Filter (Top N)
• Parameter in reference line

Dashboards and Stories

• Introduction to Dashboards
• The Dashboard Interface
• Dashboard Objects
• Building a Dashboard
• Dashboard Layouts and Formatting
• Interactive Dashboards with actions
• Designing Dashboards for devices
• Story Points

Data Security in Tableau

Optimizations tips and tricks

Interacting with Tableau Server

Working with Tableau JavaScript API

Got a question for us? Please mention it in the comments section and we will get back to you.

567