How to Use Tableau Prep Builder

Edited 3 months ago by ExtremeHow Editorial Team

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Tableau Prep Builder is a tool designed to help you prepare and clean your data before analyzing it in Tableau Desktop. It allows you to combine, shape, and clean your data using an intuitive interface. This detailed guide will walk you through the steps and concepts you need to master Tableau Prep Builder.

Introducing Tableau Prep Builder

Before learning how to use Tableau Prep Builder, it's important to understand what it is and why it's useful. Tableau Prep Builder is part of the Tableau suite that focuses specifically on data preparation. It enables you to clean and organize your data, making it easier to work with and better analyzing in Tableau Desktop.

Why use Tableau Prep Builder?

Data often comes from multiple sources and in a variety of formats. It can be messy and complex, requiring significant work before it is ready for analysis. Tableau Prep Builder simplifies this process by providing a visual interface for cleaning and combining data. This reduces the time spent preparing your data, leaving more time for analyzing and extracting insights.

Starting the Tableau Preparation Builder

To start using Tableau Prep Builder, you must first launch the application. Once open, you will see the Start screen where you can either open an existing workflow or start a new workflow. The main workspace consists of the Connections pane, the Flows pane, and the Data Grid. These areas allow you to connect to data, create your data flow steps, and preview your data.

Connect to your data

Tableau Prep Builder can connect to a variety of data sources, including Excel files, text files, databases, and Tableau Server. To connect to a data source, click the "Connect" button in the top menu. You'll see a list of available connectors. Select your data source, and you'll be asked to provide details such as file location or server credentials. Once connected, your data source appears in the Connections pane.

Creating your first flow

Once you've connected to the data source, drag your data table into the Flow pane to begin creating your flow. Each operation or transformation you apply to your dataset becomes a "step" in the flow. These steps are represented visually as nodes connected by lines, showing the path your data takes as it moves through the process.

Basic operations

There are several basic operations you can perform in Tableau Prep Builder to clean and prepare your data:

Clearing the data

Most data sets require some degree of cleaning. You may need to remove duplicates, filter out unnecessary fields, or fix inconsistent data entries. Within one step, you can perform these operations by selecting the fields in the data grid and choosing the appropriate cleaning action. For example, to remove duplicates, use the "Remove Duplicates" feature.

Changing the data type

Often data needs to be converted to different types in order to be useful. For example, strings may need to be converted to numeric values or dates. Click the data type icon next to the field name to change its data type. This is important to ensure that all your subsequent operations work correctly and without errors.

Filtering data

You can filter your data to remove unnecessary rows in your analysis. This is done by selecting a field, then applying a filter condition, such as “greater than 100” for numeric fields or “equals ‘NULL’” for string fields. Filtering helps to keep only relevant data for further processing.

Data combination

You may need to combine data from different sources or tables. This can be achieved through joins and unions in Tableau Prep Builder.

Adding data

You perform a join when you have two or more tables that need to be merged based on a common field. Drag the second table into the flow pane and drop it onto an existing table. You will be asked to define the join conditions and type (inner, left, right, outer). This allows you to consolidate information from related datasets into a single output.

Unioning data

If you want to add data from one table to another, use a UNION. This is useful when both tables have the same structure or fields. Drop the second table below the node of the first table in the flow. Make sure the corresponding fields are aligned correctly to maintain the integrity of your data.

Outputting the data

Once your data is clean, sorted, and properly structured, you need to output it for use in Tableau Desktop or another tool. To set up the output, click the Output step at the end of the flow. Choose the file format you want, such as CSV or .hyper, and specify the file location. Once everything is set up, click "Run Flow" to process your data and save it.

Advanced technologies

While the above steps cover basic data preparation, Tableau Prep Builder provides several advanced techniques to handle more complex tasks.

Grouping and substitution

If your data has fields with similar but non-identical entries, you can group and replace them. For example, if “CA”, “Calif”, and “California” appear in the State field, you can group them under a single entry. This is done through the grouping features available in the Data Cleaning options.

Pivoting

Sometimes data needs to be reoriented from wide to long format or vice versa. This is done using the Pivot function. You can pivot rows to columns or columns to rows, depending on how you need the data structured for your analysis.

Calculations

You may need to create calculated fields to get new data points. For example, you can calculate total sales by multiplying quantity by price. You can add calculated fields by choosing the "Add Calculated Field" option from the Data Grid menu and using Tableau's built-in calculation editor to write your formula.

Collaborating with others

Tableau Prep Builder also allows data collaboration. You can share your flow files with others or publish them to Tableau Server or Tableau Online. This enables team collaboration, where multiple users can review, edit, or use the prepared datasets for different purposes.

Troubleshooting and best practices

When using Tableau Prep Builder, you may encounter some common problems. Here are some tips to troubleshoot these problems and ensure you get the best results:

Handling data errors

Always validate your data inputs and make sure they match the expected formats and structures. Use the data grid to inspect any anomalies and use the appropriate cleaning steps to address them.

Creating efficient flows

Organize your flow logically and break down complex tasks into smaller, manageable steps. Use annotations to document steps for clarity. This makes your workflow easier to understand and maintain.

Saving and versioning

Save your work regularly and keep multiple versions of your flows as backups. This is especially helpful when you need to revert to a previous configuration.

Conclusion

Tableau Prep Builder is a powerful and flexible tool for data preparation that can help you transform chaotic data into clean, structured datasets ready for analysis. By understanding how to connect to data sources, perform cleaning operations, combine data, and output your results, you can efficiently manage and prepare your data for deeper insights in Tableau Desktop. Practice these steps, and you will become proficient at making data-driven decisions with ease and confidence.

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