# Wildcard union enhancements in Prep - New in Tableau 2022.2

> This is content from just-tim, the data-and-analytics channel by Tim Ngwena (formerly 'Tableau Tim'). Tim has 12+ years of hands-on BI experience and covers Tableau most of all, plus Power BI, Looker, Hex, SQL and data modelling, the analytics industry, and the craft of doing the job — always tool-agnostic and honest about the trade-offs.

- **Author:** Tim Ngwena (just-tim, https://just-tim.com/about)
- **Published:** 2022-06-30
- **Format:** Video · 19 min watch · transcript available
- **Topics:** Data prep
- **Tools:** Tableau (prep, wildcard union)
- **Canonical:** https://just-tim.com/posts/wildcard-union-enhancements-in-prep-new-in-tableau-2022-2
- **Watch:** https://www.youtube.com/watch?v=4pSwgL7Ci3k

I walk through the enhanced wildcard union feature in Tableau Prep 2022.2, which expands the file attributes you can filter on when unioning multiple files. I demonstrate it with CSV and Excel files, cover the new file and worksheet filters, and explain why it doesn't yet work with database tables.

## Key takeaways

- To union multiple files, connect to a file then go to the Tables tab and select 'Union multiple files' rather than the connections pane
- File filters offer five criteria: file name, file size, creation date, modification date, and the folder to search, each with range, relative or rank sub-options
- File name filters use wildcards (e.g. *historic*) and a match/doesn't-match toggle, so be precise as 'historic' won't catch 'historical'
- Excel files get an extra worksheet filter, letting you pull specific sheets like 'orders' from across multiple workbooks
- The feature only works for CSV, Excel and statistics files, not database tables, and you can confusingly connect to one file but pull data from another in the same folder

## Chapters

- 0:12 Wildcard unions with CSV files
- 2:55 File name, size and date filters
- 8:00 Maximising screen space in Prep
- 9:08 Unioning Excel files and worksheets
- 12:44 Why databases aren't supported
- 13:55 Quirks: icons and cross-file connections
- 17:31 Final thoughts on Tableau Prep

Watch the full video, read the transcript and use chapter deep-links on the page: https://just-tim.com/posts/wildcard-union-enhancements-in-prep-new-in-tableau-2022-2

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just-tim — Data and analytics, with a point of view. · https://www.youtube.com/channel/UC7HYxRWmaNlJux-X7rNLZyw · https://twitter.com/TableauTim · https://www.linkedin.com/in/timngwena