is anyone able to tell me if there is an efficient way to left join 3 tables on orderID column?
for uj I tried the following which is fine:
() uj/(a;b;c)
but can we do similar for a lj with xkey over orderID col?
yes this is possible, the syntax is
q)t1:([id:1 2 3] name:`a`b`c)
q)t2:([id:1 2 3] address:4 5 6)
q)t3:([id:1 2 3 4] age:10 11 12 14)
q)(lj/)(t1;t2;t3)
id| name address age
--| ----------------
1 | a 4 10
2 | b 5 11
3 | c 6 12
btw the syntax for uj should be the same (uj/)(a;b;c)