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kdb+

Add condition to where clause in q/kdb+

Table Tab

minThreshold maxThreshold point
1000 10000 10

wClause,:enlist((';~:;<);`qty;Tab[`minThreshold])

trying to incorporate maxThreshold column to where clause

qty >= MinThreshold
qty <= MaxThreshold

something like wClause,:enlist((';~:;<);`qty;Tab[`minThreshold]);Tab[`maxThreshold])

Solution 
  • q)Tab:([] minThreshold:500 1000;maxThreshold:700 2000;point:5 10)
q)Tab
minThreshold maxThreshold point
-------------------------------
500          700          5
1000         2000         10
q)select from Tab where minThreshold>=900,maxThreshold<=2500
minThreshold maxThreshold point
-------------------------------
1000         2000         10
q)parse"select from Tab where minThreshold>=900,maxThreshold<=2500"
?
`Tab
,(((';~:;<);`minThreshold;900);((';~:;>);`maxThreshold;2500))
0b
()
q)?[Tab;((>=;`minThreshold;900);(<=;`maxThreshold;2500));0b;()]
minThreshold maxThreshold point
-------------------------------
1000         2000         10

    See the whitepaper for more information on functional selects: