M Excel Source

Introduction to M Excel Source

The M Excel Source is a powerful tool for importing data from Excel files into your Power Query or Power BI environment. It leverages the Excel.Workbook function to transform and load data efficiently. This post will guide you through the process of using M Excel Source, with examples and explanations to help you understand its functionality.

Understanding Excel.Workbook Function

The Excel.Workbook function is used to connect to Excel files (.xlsx) and allows you to access tables, named ranges, and sheets within those files. It provides a flexible way to handle different data formats and structures within an Excel file.

Here's a basic syntax of the function:

In the above example, File.Contents("path/to/your/excel/file.xlsx") reads the Excel file from the specified path. The second parameter is used for specifying the nullability of columns, which is optional. The third parameter is a boolean that determines whether to promote headers (set to true if headers exist in your Excel data).

Importing Tables from Excel

To import tables from an Excel workbook, you need to use the Excel.Workbook function as part of a query. Here's a step-by-step guide:

1. Load the Excel file using File.Contents.
2. Apply Excel.Workbook to parse the file.
3. Filter the results to get the desired tables or sheets.

In this example, we load an Excel workbook located at C:/Data/Example.xlsx, parse it using Excel.Workbook, and then filter the results to access the data from Sheet1. You can adjust the Item filter to select different sheets or tables as needed.

Handling Multiple Sheets and Tables

If your Excel file contains multiple sheets or tables, you can iterate through them using a combination of the Table.SelectRows and Table.TransformColumns functions. This allows you to dynamically handle complex Excel files with multiple data segments.

This example demonstrates how to load all tables from an Excel workbook and combine them into a single table. We use Table.SelectRows to filter only table objects and Table.TransformColumns to extract the data from each table. Finally, Table.Combine merges them into one comprehensive dataset.

Conclusion

The M Excel Source with the Excel.Workbook function is an essential tool for anyone needing to integrate and manipulate Excel data within Power Query or Power BI. Understanding how to effectively use this function will significantly enhance your data processing capabilities. Experiment with different options and parameters to maximize your data import efficiency.