Template · Clean · Opening soon
Remove duplicate rows, and keep them removed
Choose the columns that make two rows the same. The template keeps one of each, the newest if you like, and says how many copies there were, every time new rows arrive.
You bring
Rows70 rows
Duplicate key
Mammoth does the work
You get
One table50 rows
One row of each, with a Copies column saying how many there were.
Your columnsCopies
- Not a spreadsheet to fill inIt is a ready-made workflow in Mammoth. You bring the files, and it does the work.
- Your files, as they areUpload a file or connect a source. Your column names do not have to match.
- Runs again by itselfWhen new data arrives, every step runs again and the result updates.
What you get back
The real result of this template, run on sample data.
Remove duplicates: the resultSample data50 rows
| First Name | Company | Last Updated | Copies | |
|---|---|---|---|---|
| ana.20@fjord.com | Ana | Fjord Outdoor | 2026-06-04 | 1 |
| ana.38@dunmore.com | Ana | Dunmore Hotels | 2026-07-28 | 1 |
| ana.3@dunmore.com | Ana | Dunmore Hotels | 2026-10-20 | 2 |
| ben.48@harbour.com | Ben | Harbour Coffee | 2026-05-05 | 1 |
| CHEN.4@ACME.COM | Chen | Acme Ltd | 2026-05-24 | 2 |
| dev.44@fjord.com | Dev | Fjord Outdoor | 2026-10-15 | 1 |
| eva.17@elm.com | Eva | Elm Street Dental | 2026-07-11 | 2 |
| ben.14@northwind.com | Ben | Northwind Traders | 2026-08-01 | 2 |
How do I remove duplicate rows from a table?
Decide which columns identify a row (an email, an ID, a name and date). Rows that agree on those, ignoring case and spacing, are duplicates; keep one and drop the rest.
- Removing duplicates once, in Excel? Read how to do it in Excel
How it works
How to use the remove duplicates template
- 1Bring your dataConnect a source, or upload a file.
- 2Check the columnsMammoth matches each column the template needs and asks only when it is unsure.
- 3Choose where it goesA table, a sheet, or a dashboard. It rebuilds on every refresh.
See the exact columns and steps ›
What it needs
Any table, and the columns that make two rows the same
Rows
- Duplicate keyTwo rows are the same when these columns agree (case and spacing ignored).
- Keep by(optional)
The steps it runs
- 1Match columns
- 2Keep one row of each
Every step is an ordinary Mammoth step you can open and change.
Remove duplicates: questions
Does it update by itself?
Yes. The template becomes an ordinary workflow in Mammoth. When your data refreshes, from a connector, a scheduled pull or a new file, every step runs again and the result table updates.
Can I change the steps?
Every step is an ordinary Mammoth step you can open and edit. Mammoth remembers which steps came from the template, so an update never overwrites your changes.
Do my column names have to match?
No. You point the template at your columns once. Mammoth suggests a match for each one and asks only when it is unsure.
Get early access to this template
Bring your data, check the columns, and the result rebuilds on every refresh.
More cleaning templates
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- Match names to a master listEach record with its master name (and ID), and how it matchedSee the template
- Duplicate invoice checkPairs of bills that look paid twice: same supplier, same amount, close dates or the same numberSee the template
- Standardise namesA Standard name for every row, so spellings of the same name group togetherSee the template
- Unpivot wide dataA long table: one row per label and period, with its valueSee the template