Create a Reusable Custom Function in Power Query M

Notes

Paste this as the entire content of a new blank query (name it, for example, fnLoadCsv), then call it elsewhere as fnLoadCsv("C:\data\sales.csv").

Requirements

• A blank query to hold the function definition.

How to use this snippet

1. In Power BI Desktop, choose Transform data to open Power Query, then open the Advanced Editor on a query (or start from a blank query).
2. Paste the snippet and replace the placeholder names (tables, columns, file paths) with your own. Check the requirements above first.
3. Run it through the Power Query M Formatter to tidy the layout.

Related Power Query M snippets

• fnBusinessDaysA reusable custom function that returns the number of weekdays between two dates.
• Write a Recursive Function with @Defines a function that calls itself using the @ self-reference operator, useful for recursive calculations like factorials.
• Build a Function That Returns Another FunctionCreates a function that, given one argument, returns a new specialized function - a pattern known as currying.
• fnCleanTextA reusable custom function that trims, cleans and proper-cases any text value passed to it.
• Define a Function with Optional ParametersCreates a custom function where some parameters are optional and fall back to a default when omitted.
• Wrap Conditional Logic in a Reusable FunctionMoves a conditional expression into its own function so it can be reused and tested independently of a table step.

More Power Query M resources

Browse all 145 snippets in the Power Query M Code Snippets, or search the library for something similar to Create a Reusable Custom Function.