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K code in functional query 2
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Give functional form for:
select sum size by ticker:((string[id],:”.”),’string[ex])from trade_usq where any not null(size;price)
After doing
parse”select sum size by ticker:((string[id],’\”.\”),’string[ex])from trade_usq where any not null(size;price)”
I get;
? `trade_usq ,,(max$["b"];(~:;(^:;(enlist;`size;`price)))) (,`ticker)!,((';,);((';,);($:;`id);".");($:;`ex)) (,`size)!,(sum;`size)I have then wrote out;
?[`trade_usq;enlist(max$[“b”];(~:;(^:;(enlist;`size;`price))));(enlist`ticker)!enlist((‘;enlist);((‘;enlist);($:;`id);”.”);($:;`ex));(enlist`size)!enlist(sum;`size)]
But this doesn’t seem to work? What is wrong with this?
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2 Replies
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Note that you never need to use `each` with `string`. `string` already implicitly expands over lists.
When using `parse` on a q expression, any functions in the `.q` namespace are replaced by their definition. You can type `.q` at the prompt to see these definitions, and if you work in q enough, you will learn to recognize them.
`k){x/:y}` stands for `sv`
`k){x’y}` stands for `each`, which is redundant as mentioned above
So the full query would look like
`</span><span style=”font-family: inherit; font-size: inherit;”>“</span></p><p>![t;();0b;enlist[`ric]!enlist(`$;(“.”sv/:;(string;(flip;(enlist;`sym;`exch)))))]</p><p>“`
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[Reposting answer above as plain text for readability]
Note that you never need to use each with string. string already implicitly expands over lists.When using parse on a q expression, any functions in the .q namespace are replaced by their definition. You can type .q at the prompt to see these definitions, and if you work in q enough, you will learn to recognize them.
k){x/:y} stands for sv
k){x’y} stands for each, which is redundant as mentioned above
So the full query would look like
![t;();0b;enlist[`ric]!enlist(`$;(“.”sv/:;(string;(flip;(enlist;`sym;`exch)))))]
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This reply was modified 3 days, 8 hours ago by mwoods.
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This reply was modified 3 days, 8 hours ago by
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