5 Ways to Merge Excel Sheets in Tableau Easily

If you're working with large datasets in Tableau and need to merge information from multiple Excel sheets, you've come to the right place. Merging Excel sheets in Tableau can be a game-changer, simplifying your data analysis process and enabling you to create more dynamic and comprehensive visualizations. In this comprehensive guide, we'll explore 5 effective methods to combine Excel sheets seamlessly in Tableau. Whether you're a data analyst, marketer, or a business intelligence professional, mastering these techniques will enhance your workflow and provide a clearer picture of your data.

Method 1: Data Blending

Data blending in Tableau is one of the most straightforward ways to merge sheets from different data sources. Here’s how you can do it:

• Connect to your first Excel file in Tableau.
• Repeat the process to connect to your second Excel file or any subsequent files.
• Use the Data Pane to switch between data sources and start blending.

When blending, Tableau creates a virtual connection based on a common dimension found in both datasets. For instance, if you have two Excel sheets where one contains sales data and another contains customer data, you could blend these on a common 'Customer ID' field.

Key Points for Effective Blending:

• Use a Common Field: Ensure there’s a field that exists in both datasets to link them logically.
• Understand Relationship Types: Blending supports both left and right joins, so choose the appropriate relationship based on your analysis needs.

🗣️ Note: Data blending might not perform well with very large datasets or complex calculations. Consider other methods for such cases.

Method 2: Cross-Database Join

The cross-database join in Tableau allows you to physically combine data from different sources, providing a more robust solution than blending. Here’s the process:

• Connect to your first Excel file in Tableau.
• Add additional connections to other Excel files.
• In the Data Pane, drag and drop the tables you want to join into the canvas area.
• Define the join conditions by dragging fields from one table to another.

Note that Tableau supports several types of joins, which you can utilize based on your data requirements.

Benefits of Cross-Database Join:

• True Relational Connection: Unlike blending, cross-database joins provide a true relational connection, allowing for more complex and efficient data manipulation.
• Better Performance: This method can be faster than blending for large datasets since it happens at the database level.

Method 3: Custom SQL

Custom SQL is an advanced technique in Tableau to merge data from multiple Excel sheets. Here’s how to use it:

• After connecting to your first Excel file, select ‘Use Custom SQL’ from the data source.
• Write SQL to combine data from different sheets or even from different Excel files.

Here's an example of SQL to union two Excel sheets:

SELECT * FROM [Sheet1$]
UNION ALL
SELECT * FROM [Sheet2$]

🗣️ Note: Custom SQL requires some SQL knowledge. If you're new to SQL, you might want to practice or seek assistance.

Considerations for Custom SQL:

• Flexibility: You have full control over the data transformation and combining process.
• Complexity: Ensure that your SQL queries don’t become too complex for Tableau to handle efficiently.

Method 4: Data Prep (Tableau Prep)

Tableau Prep is a separate tool designed specifically for data preparation. Here’s how you can use it:

• Import your Excel sheets into Tableau Prep.
• Use Join or Union steps to merge the data. For instance, you can join two tables on a common field or union them to stack rows from different sheets.
• Save the combined dataset as an Extract or Publish to Tableau Server for later use in Tableau Desktop.

This method is excellent when:

• You need to clean or reshape data before analysis.
• Your data requires initial transformation steps not easily handled in Tableau Desktop.

Advantages of Using Tableau Prep:

• Pre-processing: Clean and prepare data before it reaches Tableau Desktop, saving time and resources.
• Visual Data Flow: See how data is transformed through a visual workflow, making it easier to understand and audit the process.

Method 5: Using Calculated Fields

If direct data combining isn't feasible or necessary, you can use calculated fields in Tableau to merge data from multiple sheets:

• Create calculated fields that reference data from different sheets.
• Use LOD (Level of Detail) expressions to analyze aggregated data at different levels.

When to Use Calculated Fields:

• Limited Data Sharing: When you can't physically merge data due to privacy or system constraints.
• Complex Analysis: To perform advanced calculations or to create views that aren't possible with direct joins or unions.

The recap of merging Excel sheets in Tableau reveals a variety of strategies tailored to different scenarios and data needs:

• Data Blending for quick and simple data integration.
• Cross-Database Join for more complex, performance-intensive merging.
• Custom SQL for advanced users who want full control over the merging process.
• Tableau Prep for pre-processing and preparing your data before analysis.
• Calculated Fields for when direct data combining isn't feasible or necessary.

Remember, the choice of method depends on:

• The complexity of your dataset.
• The performance requirements of your analysis.
• Your proficiency with SQL or data preparation tools.

By mastering these methods, you'll be able to combine data from various Excel sheets in Tableau, leading to more comprehensive data analysis and powerful visualizations that drive insights and business decisions.

Can I use these methods to merge sheets from different Excel files?

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Yes, you can use cross-database joins, data blending, or Tableau Prep to combine sheets from different Excel files. Custom SQL requires the files to be connected first but then provides full flexibility in merging.

Which method should I use for large datasets?

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For large datasets, consider using cross-database joins or data preparation with Tableau Prep for better performance. Avoid data blending if possible, as it might not handle large datasets efficiently.

Do I need to know SQL to merge Excel sheets in Tableau?

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Not necessarily. While Custom SQL requires SQL knowledge, methods like data blending and Tableau Prep provide visual interfaces that don’t require SQL expertise.

What if my data sources are in different formats?

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Tableau can connect to various data sources like SQL databases, Google Sheets, and more. You’ll need to ensure your data is structured similarly or use ETL processes to make them compatible for merging.