• kdb+

  How does (first”) works?

  Posted by kdb_newbie on June 25, 2023 at 12:00 am

  dict:`a`b`c!((enlist 1; enlist `a);(enlist 2;enlist `b);(enlist 3;enlist `c))
  q)(first”) dict
  a| 1 `a
  b| 2 `b
  c| 3 `c
  q)(first’) dict
  a| 1
  b| 2
  c| 3
  q)

  How does (first”) work, please? And then how would (first”’) work?
  Thank you!

  kdb_newbie replied 8 months, 2 weeks ago 2 Members · 1 Reply
• 1 Reply

• 

  rocuinneagain

  Member

  June 26, 2023 at 12:00 am

  https://code.kx.com/q/ref/maps/#each

  ' operates the same as each in these cases

   

   

  (first'') dict 
  a| 1 `a 
  b| 2 `b 
  c| 3 `c 
  
  {first each x} each dict 
  a| 1 `a 
  b| 2 `b 
  c| 3 `c 
  
  (first')dict 
  a| 1 
  b| 2 
  c| 3 
  
  first each dict 
  a| 1 
  b| 2 
  c| 3

   

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