Suppose I have a table
q) t:([]
name:`c`c`c`w`w;
id:1 1 1 2 1;
c:2 4 5 4 3
);
q)show t;
name id c
---------
c 1 2
c 1 4
c 1 5
w 2 4
w 1 3
and I would like to get the first row given the composite grouping of name and id.
Since I only have one column I can do
q)select first c by name,id from t
name id c
---------
c 1 2
w 2 4
w 1 3
which gives me the required result. However, suppose I have several other columns (apart from name, id, c) making it inconvenient to type
select first c, first col1, first col2, ...,first colN by name,id from t
Is there something terser?
Use fby https://code.kx.com/q/ref/fby/#tables
q)select from t where i=(first;i) fby ([] name; id)
name id c
---------
c 1 2
w 2 4
w 1 3
q)