With JSL, how to split a datatable by distinct values in a column?

[#1]

Hello, I'm a starter of JSL and I have a question :grinning_face:

For example, I have a data table, and I want to divide (subset) it into several data tables, by the values of B column.

A  B  C       A  B  C       A  B  C
1  1  1  =>   1  1  1  AND  3  2  6
2  1  4       2  1  4       2  2  1
3  2  6                     5  2  3
2  2  1
5  2  3

I know how to Subset a data table, or how to select rows according to B values (Select Where), but I don't know how to get a list of all distinct values in column B (just like  SELECT DISTINCT statement in SQL) without go through all the rows.

What is the best way to do this work?

Thank you.

[#2 · Accepted solution]

Hi @Setsuna,

I believe you are looking for the 'By' option in Subset:

Names Default To Here( 1 );

dt = Open( "$Sample_data/big class.jmp" );

dtSubs = dt << Subset( All rows, Selected columns only( 0 ), By( :age ) );

//dtSubs is a list of data table references:
dtSubs[1] << Set Name("First table")

[#3]

Thank you very much! That's exactly what I want.