When to use this Power Query pattern
Use this pattern when the same data preparation step needs to happen every time a file, table or report refreshes.
Syntax or pattern
Table.TransformColumnTypes(Source, {{"OrderDate", type date}, {"Sales", type number}})Typical UI steps
- Open Power Query Editor.
- Select the relevant column or query.
- Apply the transformation from the ribbon or formula bar.
- Review the generated step.
- Check data types and row counts before loading.
5 practical examples
Use Table.TransformColumnTypes in a sales report
This example shows how to use Table.TransformColumnTypes when preparing a sales report.
Table.TransformColumnTypes(Source, {{"OrderDate", type date}, {"Sales", type number}})Use this pattern when the sales report needs a repeatable transformation instead of manual cleanup.
Use Table.TransformColumnTypes in a customer list
This example shows how to use Table.TransformColumnTypes when preparing a customer list.
Table.TransformColumnTypes(CleanSource, {{"OrderDate", type date}, {"Amount", type number}})Use this pattern when the customer list needs a repeatable transformation instead of manual cleanup.
Use Table.TransformColumnTypes in a inventory export
This example shows how to use Table.TransformColumnTypes when preparing a inventory export.
Table.TransformColumnTypes(Inventory, {{"OrderDate", type date}, {"Units", type number}})Use this pattern when the inventory export needs a repeatable transformation instead of manual cleanup.
Use Table.TransformColumnTypes in a monthly dashboard
This example shows how to use Table.TransformColumnTypes when preparing a monthly dashboard.
Table.TransformColumnTypes(ReportData, {{"Date", type date}, {"Revenue", type number}})Use this pattern when the monthly dashboard needs a repeatable transformation instead of manual cleanup.
Use Table.TransformColumnTypes in a operations tracker
This example shows how to use Table.TransformColumnTypes when preparing a operations tracker.
Table.TransformColumnTypes(Tracker, {{"OrderDate", type date}, {"Hours", type number}})Use this pattern when the operations tracker needs a repeatable transformation instead of manual cleanup.
Common mistakes to avoid
- Applying steps in an order that makes later cleaning harder.
- Forgetting that step names are referenced by later M code.
- Not checking row counts before and after transformations.
FAQ
When should I use Table.TransformColumnTypes in Power Query?
Use Table.TransformColumnTypes when the transformation should be repeatable every time the data refreshes.
Can I do Table.TransformColumnTypes from the Power Query interface?
Usually yes. The interface creates the M code for many common transformations, and you can adjust it in the formula bar or Advanced Editor.
Should I edit the M code manually?
Edit M manually when the interface cannot express the pattern clearly, or when you need reusable logic, parameters or cleaner step names.