• abs() vs abs[] for fby “while” all() vs all[]

  abs() vs abs[] for fby “while” all() vs all[]

  Posted by kdb_newbie on May 18, 2024 at 12:14 pm

  May I ask how does abs() differs from abs[] in a select statement using fby clause?

  q)tab:([] sym:g1g3g1g1g2g3; price:-2.5 2 -0.5 -0.2 3 4)
  q)tab
  sym price
  ---------
  g1  -2.5 
  g3  2    
  g1  -0.5 
  g1  -0.2 
  g2  3    
  g3  4    
  q)select from tab where abs(price)=({abs max x};price) fby sym
  'type
    [0]  select from tab where abs(price)=({abs max x};price) fby sym
         ^
  q)

  and also similarly, in my qsql, if I use all with square brackets, it throws a rank error but all() works fine

  select from xxx where all[col=a;col2=b] //rank error

  How do I know when to use [] vs ()
  Thank you!

  replied 1 year ago 0 Member · 0 Replies
• 0 Replies

Log In to Reply