Is it possible to use outerjoin for more than two tables?

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Stefan Azzopardi 2018-6-14

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评论： Peter Perkins 2018-7-3

Is it possible to use the function 'outerjoin' in Matlab for more than 2 tables? Basically, I have a number of variables (around 15), all in table (1x2) having one column timestamp and another column variable. I am trying to join all variables in one table to finally make some calculations. The method of outerjoin worked perfectly for the first 2 tables but could not add more than 2 variables.

If this is not possible, is there an alternative way on how should I proceed?

Regards

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Stefan Azzopardi 2018-6-17

I have tried the loop but it gives error, which I managed to fix. Still the names of the columns end up to be renamed by Matlab so that one still can verify the name. Also, I have around 15 tables to join and therefore this would take an infinintely big loop and therefore I was asking whether there was an alternative way in which one could perform this operation.

Peter Perkins 2018-7-3

It's kind of impossible to tell from your description, but it may be that you want to merge the keys, which is not the default in an outerjoin.

I would think that the bigger problem would be that doing an outerjoin on 15 tables would give you a very large number of rows, unless there are few if any non-matches, in which case you might consider an innerjoin.

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Answer 1

Stefan Azzopardi 2018-6-14

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Am still finding problems trying this way:

s = outerjoin (Timestamp, J_Incoming)
s.Timestamp_J_Incoming = []
d = outerjoin (s, CP_Incoming)

in this section it is giving me error on variable 'd'. Timestamp is 1 column of time, J_Incoming and CP_Incoming contains 2 columns each, 1 Variable and 1 Timestamp. Using 's', I have created a table with 1 Timestamp and 1 Variable (J) after clearing on of the J_Timestamp. It is still giving me error "Cannot find a common table variable to use as a key variable." The variable on CP_ Incoming is timestamp