# How to associate two tables?

Hi! I'm new to KNIME and am seeing huge potential here for this to manage our lab's (very large) store of data. Got some very beginner level questions:

How do i associate two tables together?

eg: Table 1 -

A1  A2  A3  A4  A5

B1  B2  B3  B4  B5

Table2:

123  22  210  102  11

45  568  52  445  142

I would like to get a list at the end with this sort of data:

Result:

1. A1 - 123

2. A2 - 22

..etc..

8. B3 - 52

Any suggestions? I've tried table joiner, but it doesn't give me the output I'd like.

Thanks!

Probably the fastest way to do this is to simply unpivot the two tables data and then join (or column append) them together. Once you have the data in a skinny format, you can pivot it back to any shape that is handy for analysis.

Regards,

Aaron

Excellent! Thanks! That worked perfectly. One follow-up question (unrelated to OP topic):

I have three 2-dimensional tables: T1, T2, T3. I want a fourth table T4 which is also 2D and contains the average of T1, T2, T3 at each position - any suggestions on the best method ?

eg. T1=

2 1 3

4 1 5

T2 =

3 4 5

4 5 6

Result:

3 2.5 4

4 3 5.5

(I think Result[0,0] should be 2.5 or T1[0,0] should be 3 or T2[0,0] should be 4 or some other combination.)

I would join T1, T2, ... and after that use Column Aggreagator to average the results (This should be done in a loop though for each original column and the new column name should be computed with the Java Edit Variable node).

Cheers, gabor

What Gabor said - computing means externally and only using KNIME for joining is to vastly underexploit its functionality. :-)

Cheers
E