12 Replies Latest reply on Dec 20, 2011 5:55 PM by Jon Mitten

# How to determine first purchase date

I would like to create a sheet that has a list of books and the first date that book sold. Do I need to make a formula / calculation for that, or is there an easier way to filter by date of first appearance in the data-source?

• ###### 1. Re: How to determine first purchase date

What does your data look like? Generally speaking, you would need to use table calculations to find the first record for each book, unless data already has it as a separate column.

• ###### 2. Re: How to determine first purchase date

I have a date in a separate column, for each transaction.

• ###### 3. Re: How to determine first purchase date

Then this is easy - create custom table calculation using

`TOTAL(MIN([book sale date]))`
and set it to compute along [book sale date] and "Bob's your uncle". [book sale date] is the name of your date field, of course, modify it as needed.

See attached workbook for an example. I used sample data, pretend that products are books, and order dates are your dates.

• ###### 4. Re: How to determine first purchase date

The original question sounds even simpler than this.  Just put [Book] and MIN([Sale Date]) on the rows shelf.

Dimitri's method is necessary if you want to have all the details of the first sale and/or information about all sales available in the view.

• ###### 5. Re: How to determine first purchase date

So I have a similar problem to this. Assume I have 2 columns, a date, and a user id, and I want to create a graph that essentially shows days vs "first time we see users", which would allow us to determine our most popular "start" dates

• ###### 6. Re: How to determine first purchase date

Brian, try Richard's solution above.

• ###### 7. Re: How to determine first purchase date

Jon, unfortunately I don't see that working for me:

http://i.imgur.com/raP9j.png

• ###### 8. Re: How to determine first purchase date

Put your date pill in the column shelf...

• ###### 9. Re: How to determine first purchase date

That didn't change anything?

http://i.imgur.com/C0aoi.png

• ###### 10. Re: How to determine first purchase date

You're aggregating... you shouldn't be. The date should be raw, the First appearance should be MIN([date]) or however you name your date fields.

• ###### 11. Re: How to determine first purchase date

1) create calculated field from starttime

2) MIN([starttime])

3) this is new field now an aggregation.

I can't make it not an aggregation.

• ###### 12. Re: How to determine first purchase date

Change to Distinct? Instead of Continuous? Try that.