Chapter 1.  Creating Your First Visualizations and Dashboard

Tableau is an amazing platform for seeing, understanding, and making key decisions based on your data. With it, you can achieve incredible data discovery, analysis, and storytelling. You'll accomplish these tasks and goals visually using an interface that is designed for a natural and seamless flow of thought and work. Tableau accomplishes this using VizQL, a visual query language. You won't have to learn VizQL. It's all done behind the scenes and you won't be forced to write tedious SQL scripts, MDX code, or painstakingly work through numerous wizards to select a chart type and then link everything to data.

Instead, you will be interacting with your data in a visual environment where everything that you drag and drop will be translated into the necessary queries and then displayed visually. You'll be working in real-time, so you will see results immediately, get answers as fast as you can ask questions, and be able to iterate through dozens of ways to visualize the data to find a key insight or tell a piece of the story.

Tableau allows you to accomplish numerous tasks, including:

• Data connection, integration, and preparation: Tableau allows you to connect to data from sources and, if necessary, create a structure that is ready to use. Most of the time this is as easy as pointing Tableau to a database or opening a file, but Tableau gives you the tools to bring together even complex and messy data from multiple sources.
• Data exploration: You can visually explore a dataset using Tableau in order to understand what data you have.
• Data visualization: This is the heart of Tableau. You can iterate through the countless ways of visualizing the data to ask and answer questions, raise new questions, and gain new insights.
• Data analysis: Tableau has an ever growing set of analytical functions that allow you to dive deep into understanding complex relationships, patterns, and correlations in the data.
• Data storytelling: Tableau allows you to build fully interactive dashboards and stories with your visualizations and insights so that you can share the data story with others.

We'll take a look at each of these tasks in the subsequent chapters. This chapter introduces the foundational principals of Tableau and focuses on data visualization. We'll accomplish this through a series of examples that will introduce the basics of connecting to data, exploring and analyzing the data visually, and finally putting it all together in a fully interactive dashboard. These concepts will be developed far more extensively in the subsequent chapters. But don't skip this chapter, as it introduces key terminology and foundational concepts, including:

• Connecting to data
• Foundations for building visualization
• Visualizing the data
• Creating bar charts
• Creating line charts
• Creating geographic visualizations
• Using Show Me
• Bringing everything together in a dashboard

Connecting to data

Tableau connects to data stored in a wide variety of files and databases. This includes flat files, such as Excel and text files; relational databases, such as SQL Server and Oracle; cloud-based data sources, such as Google Analytics and Amazon Redshift; and OLAP data sources, such as Microsoft Analysis Services. With very few exceptions, the process of building visualizations and performing analysis will be the same no matter what data source you use. We'll cover the details of connecting to different data sources in Chapter 2, Working with Data in Tableau.

For now, we'll connect to a text file, specifically, a comma-separated values file (.csv). The data itself is a variation of the sample data provided with Tableau for Superstore, a fictional retail chain that sells various products to customers across the United States. It's preferable to use the supplied data file instead of the Tableau sample data as the variations will lead to differences in visualizations.

The Chapter 1 workbook, included with the code files bundle, already have connections to the file; however, for this example, we'll walk through the steps of creating a connection in a new workbook:

1. Open Tableau; you should be able to see the home screen with a list of connection options on the left, thumbnail previews of recently edited workbooks in the center, links to various resources on the right, and sample workbooks on the bottom.
2. Under Connect and To a file, click Text File.
3. In the Open dialogue box, navigate to the \Learning Tableau\Chapter 01\ directory and select the Superstore.csv file.
4. You will now see the data connection screen, which allows you to visually create connections to data sources. We'll examine the features of this screen in detail in the Connecting to data section of Chapter 2, Working with Data in Tableau. For now, notice that Tableau has already added and given a preview of the file for the connection:
5. For this connection, no other configuration is required, so simply click on the Sheet 1 tab at the bottom to start visualizing the data! You should now see the main work area within Tableau, which looks similar to the following screenshot:

We'll refer to elements of the interface throughout the book using specific terminology, so take a moment to get familiar with the terms used for various components numbered in the preceding image:

1. The menu contains various menu items for performing a wide range of functions.
2. The toolbar allows for common functions, such as undo, redo, save, adding a data source, and so on.
3. The sidebar contains tabs for Data and Analytics. When the Data tab is active, we'll refer to the sidebar as the data pane. When the Analytics tab is active, we'll refer to the sidebar as the analytics pane. We'll go into detail later in this chapter, but for now, note that the data pane shows the data source at the top and contains a list of fields from the data source and is divided into dimensions and measures.
4. Various shelves, such as Columns, Rows, Pages, and Filters, serve as areas to drag and drop fields from the data pane. The Marks card contains additional shelves, such as Color, Size, Text, Detail, and Tooltip. Tableau will visualize data based on the fields you drop on the shelves.

   Note

   
   

   Data fields in the data pane are available to be added to the view. Fields that have been dropped on a shelf are called in the view or active fields, because they play an active role in the way Tableau draws the visualization.

5. The canvas or view is where Tableau will draw the data visualization. You may also drop fields directly onto the view. In Tableau 10, you'll observe the seamless title at the top of the canvas. By default, it will display the name of the sheet, but it can be either edited or hidden.
6. Show Me is a feature that allows you to quickly iterate through various types of visualizations based on data fields of interest. We'll look at Show Me towards the end of the chapter.
7. The tabs at the bottom of the window gives you the option of editing the data source, as well as navigating between and adding any number of sheets, dashboards, or stories. Many times a tab (whether it is a sheet, dashboard, or story) is referred to, generally, as a sheet. We'll also often use these specific terms for a tab:
   • A sheet: A sheet is a single data visualization (such as a bar chart or line graph). Since sheet is also a generic term for any tab, we'll often refer to a sheet as a view because it is a single view of the data.
   • A dashboard: A dashboard is a presentation of any number of related views and other elements (such as text or images) arranged together as a cohesive whole to communicate a message to an audience. Dashboards are often interactive.
   • A story: A story is a collection of dashboards or single views arranged to communicate a narrative from the data. Stories can also be interactive.

   Note

   
   

   A Tableau workbook is the collection of data sources, sheets, dashboards, and stories. All of this is saved as a single Tableau workbook file (.twb or.twbx). We'll look at the difference in file types and explore details of what else is saved as a part of a workbook in later chapters.

8. As you work, the status bar will display important information and details about the view and selections.
9. Various controls allow you to navigate between sheets, dashboards, and stories, as well as view the tabs as a filmstrip...