6 Replies Latest reply on Jul 11, 2018 6:05 AM by Doug Spavlik

Joining datasets

Ivory Peng Jul 10, 2018 8:33 AM

I need to join 3 datasets A, B, and C.

First need to join B and C, left join, keep all entries in B (suppose this joint dataset name BC)

Then I will join A and BC, left join, keep all entries in A

I can't join A and B directly because no common identifiers exist between them (identifiers exist between B&C, and A&C)

These steps are very easy to complete in R. Can I do it in Tableau and skip R?

Thanks.

1. Re: Joining datasets

kunal.dongre.0 Jul 10, 2018 8:59 AM (in response to Ivory Peng)

Are A,B & C tables? If yes, then you can write a custom SQL query.
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2. Re: Joining datasets

Ivory Peng Jul 11, 2018 5:27 AM (in response to kunal.dongre.0)

Yes they are tables. I will try SQL query. Thank you
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3. Re: Joining datasets

Doug Spavlik Jul 11, 2018 5:35 AM (in response to Ivory Peng)

You should be able to join the tables by dragging and dropping them on to the Canvas on the Data Source Page. Check out this thread. Join data from 3 tables in one database

If this is helpful please remember to mark it as such. Thanks!
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4. Re: Joining datasets

Ivory Peng Jul 11, 2018 5:54 AM (in response to Doug Spavlik)

Thanks Doug for your reply. I tried but this scheme is not working for me. I have to join table A after I join B and C, since I don't have clause to join A and B directly.
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5. Re: Joining datasets

Jim Dehner Jul 11, 2018 5:58 AM (in response to Ivory Peng)

Good morning
You would be able to do this using Tableau Prep
Tableau Prep
https://onlinehelp.tableau.com/current/prep/en-us/help.html#prep_get_started.html

Jim
If this posts assists in resolving the question, please mark it helpful or as the 'correct answer' if it resolves the question. This will help other users find the same answer/resolution. Thank you.
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6. Re: Joining datasets

Doug Spavlik Jul 11, 2018 6:05 AM (in response to Ivory Peng)

So could you drag B and C to the canvas, create the join the drag table A to the canvas to join on C
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