Bonbon's Guide To Data & Tech

What are the benefits of using VBA with Power Query?

Using VBA in conjunction with Power Query can provide significant benefits, especially when you need to automate complex workflows, integrate data from multiple sources, or perform advanced transformations programmatically. Here are the key benefits of using VBA over just using Power Query directly:

1. Automation and Repetition:
   • Automation: VBA allows you to automate repetitive tasks, such as importing data from multiple files, applying the same transformations, and saving the results in a consistent format.
   • Scheduling: You can schedule VBA macros to run at specific times, ensuring data is updated automatically.
2. Customization and Flexibility:
   • Custom Functions: VBA enables you to create custom functions and procedures that can be used within Power Query M code.
   • Dynamic Parameters: You can pass dynamic parameters to Power Query queries using VBA, allowing for more flexible data processing. This alone is a huge benefit!!
3. Integration with Other Applications:
   • Interoperability: VBA can interact with other applications and services, such as databases, web APIs, and email clients, enhancing the capabilities of Power Query.
   • Data Export: You can use VBA to export data to various formats, such as PDF, CSV, or other Excel files, after it has been processed by Power Query.
4. Complex Logic and Control:
   • Conditional Logic: VBA provides powerful conditional logic and control structures that can be used to handle complex data processing tasks.
   • Error Handling: You can implement robust error handling in VBA to manage unexpected issues during data processing.
5. User Interface:
   • Custom UserForms: VBA allows you to create custom user interfaces (UserForms) for data entry and interaction, making it easier for users to perform complex tasks without needing to know Power Query M code.
   • Buttons and Macros: You can add buttons and macros to Excel worksheets to trigger VBA scripts, making it user-friendly.
6. Advanced Data Manipulation:
   • Data Cleaning: VBA can be used for advanced data cleaning tasks, such as removing specific patterns, handling missing data, and normalizing data formats.
   • Data Transformation: VBA can perform complex transformations that might be difficult or impossible to achieve with Power Query alone.
7. Version Control and Collaboration:
   • Version Control: VBA code can be version-controlled using tools like Git, allowing for better collaboration and tracking changes.
   • Shared Macros: You can share VBA macros with your team, ensuring consistency in data processing workflows. This can be especially helpful for vacation coverage or spreading the workload among multiple team members!
8. Performance Optimization:
   • Efficiency: For large datasets, VBA can be more efficient in certain scenarios, especially when combined with Power Query for initial data loading and filtering.
   • Resource Management: VBA can manage system resources more effectively, ensuring smooth performance during data processing.

When to Use VBA Over Power Query

• Complex Workflows: When you need to perform a series of complex transformations and data manipulations that are difficult to achieve with Power Query alone.
• Integration with Other Systems: When you need to integrate Excel with other applications, databases, or web services.
• Automated Reporting: When you need to automate the generation of reports and dashboards based on dynamic data sources.
• Custom User Interfaces: When you need to create custom user interfaces for data entry and interaction.
• Advanced Error Handling: When you need robust error handling and logging for data processing tasks.

When to Use Power Query Alone

• Simple Data Transformation: When you need to perform simple data transformations and cleaning tasks.
• Data Visualization: When you need to create dynamic data visualizations and dashboards.
• Data Integration: When you need to integrate and combine data from multiple sources without complex logic.
• Data Refresh: When you need to refresh data regularly from external sources.
• Data Transformation: Power Query allows for complex data transformations, such as filtering, merging, and aggregating data.
• Refreshable Data: Data imported using Power Query can be easily refreshed to update with new data.
• Scalability: Power Query is better suited for larger datasets and more complex data processing tasks.

VBA with Power Query Code Samples with Explanations

Use Case: Importing Data from CSV Files Using Power Query

Power Query is a more advanced and flexible tool for data import and transformation in Excel. It allows for more complex data transformations and can handle larger datasets more efficiently. Here’s how you can use VBA to import a CSV file using VBA with Power Query.

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Explanation of Power Query VBA Code

1. File Path and Connection Name:
   • filePath is the path to your CSV file
   • connName is the name of the Power Query connection.
2. Delete Existing Connection:
   • The code checks if the connection already exists and deletes it to avoid conflicts.
3. Create New Power Query Connection:
   • The Queries.Add method creates a new Power Query connection.
   • The Formula parameter specifies the Power Query M code to import and transform the CSV file.
4. Load Query into Worksheet:
   • A new worksheet is created, and the query is loaded into it using LoadFromText

Use Case: Importing and Transforming Data from an Excel File Using Power Query and VBA

Objective: Import data from a specific worksheet in an Excel file, filter out rows with specific criteria, perform some transformations, and load the cleaned data into a new worksheet.

Preparation:

1. Prepare the Source Excel File:
   • Ensure your source Excel file is located at a known path, e.g., C:\Data\source_data.xlsx.
   • Ensure the data is in a worksheet named SalesData.
2. VBA Code to Import and Transform Data Using Power Query:

Explanation of the VBA Code

1. Set File Path, Workbook Name, Sheet Name, and Names:
   • sourceFilePath is the path to your source Excel file.
   • sourceWorkbookName is the name of the source Excel file.
   • sourceSheetName is the name of the worksheet containing the data.
   • connName is the name of the initial Power Query connection.
   • queryName is the name of the transformed Power Query query.
2. Delete Existing Connection and Query:
   • The code checks if the connection and query already exist and deletes them to avoid conflicts.
3. Create a New Power Query Connection:
   • The Queries.Add method creates a new Power Query connection to import data from the specified worksheet in the Excel file.
   • The Formula parameter specifies the Power Query M code to import the data.
4. Create a New Power Query Query for Transformation:
   • This query uses the initial connection as its source.
   • It skips the first row (assuming headers).
   • It removes duplicates based on specified columns.
   • It filters rows where Sales is greater than 100.
   • It sorts the filtered rows by Date in ascending order.
   • It adds a new column TotalSales calculated as Sales * Quantity.
5. Load the Transformed Query into a New Worksheet:
   • A new worksheet is created, and the transformed query is loaded into it using LoadFromText.
6. Format the Worksheet:
   • The code automatically fits the columns and applies a table style for better readability.

Detailed Steps

1. Prepare the Source Excel File:
   • Update the path to match your source Excel file.
   • Ensure the data is in a worksheet named SalesData, or update that variable to match your data.
2. Open VBA Editor:
   • Press Alt + F11 to open the VBA editor.
3. Insert a New Module:
   • In the VBA editor, go to Insert > Module to create a new module.
4. Copy and Paste the VBA Code:
   • Copy the above VBA code and paste it into the module.
5. Run the Macro:
   • Close the VBA editor and return to Excel.
   • Press Alt + F8, select ImportAndTransformExcelDataWithPowerQuery, and click Run.
6. View the Results:
   • A new worksheet named TransformedData will be created, showing the imported and transformed data.

Additional Tips

• Customizing Columns:
  • You can customize the column names and the criteria for filtering and sorting based on your specific dataset.
• Handling Different Workbooks and Sheets:
  • Adjust the sourceFilePath, sourceWorkbookName, and sourceSheetName variables to match your source file and worksheet.
• Error Handling:
  • Add error handling to manage potential issues, such as file not found or invalid data.

Example: Combining VBA with Power Query for Automation of Reporting

Here’s a more detailed example that combines VBA with Power Query to automate a complex data processing workflow that can automate data reporting from start to finish, including transforming the data and outputting a user-friendly report.

Use Case: Automating Data Import, Transformation, and Reporting

Objective: Import data from multiple Excel files, perform transformations, and generate a consolidated report.

VBA Code:

Explanation of the VBA Code

1. Set Folder Path and Names:
   • folderPath is the path to the folder containing the Excel files.
   • connName is the name of the initial Power Query connection.
   • queryName is the name of the transformed Power Query query.
2. Delete Existing Connection and Query:
   • The code checks if the connection and query already exist and deletes them to avoid conflicts.
3. Initialize a New Worksheet:
   • A new worksheet named ConsolidatedData is created to store the consolidated data.
4. Loop Through Excel Files:
   • The code loops through all Excel files in the specified folder.
   • For each file, it creates a new Power Query connection to import data from the SalesData worksheet.
5. Create a New Power Query Query for Transformation:
   • This query uses the initial connection as its source.
   • It skips the first row (assuming headers).
   • It removes duplicates based on specified columns.
   • It filters rows where Sales is greater than 100.
   • It sorts the filtered rows by Date in ascending order.
   • It adds a new column TotalSales calculated as Sales * Quantity.
6. Load the Transformed Query into the Consolidated Worksheet:
   • The transformed data is loaded into the ConsolidatedData worksheet.
7. Delete the Power Query Connection and Query:
   • After processing each file, the connection and query are deleted to clean up.
8. Format the Worksheet:
   • The code automatically fits the columns and applies a table style for better readability.

Conclusion

Using VBA in conjunction with Power Query provides a powerful combination for automating and managing complex data workflows. While Power Query is excellent for data transformation and integration, VBA offers the flexibility and control needed for advanced automation and integration tasks. By combining these tools, you can create robust and efficient data processing solutions.

Feel free to comment other examples you would like to see as we continue to explore automation of workflows via both VBA and Power Query!