Add condition to where clause in q/kdb+ - kdb

Question

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])

Answer 1

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:
https://code.kx.com/q/wp/parse-trees/

Answer 2

Is your problem
you have a Where phrase that works for functional qSQL and you want to extend it?
you want to select rows of a table where the value of a quantity falls within an upper and lower bound?
If (2) you can use Join Each to get the bounds for each row, and within to test the quantity.
q)show t:([]lwr:1000 900 150;upr:10000 25000 500;qty:10 1000 450)
lwr upr qty
---------------
1000 10000 10
900 25000 1000
150 500 450
q)select from t where qty within' lwr{x,y}'upr
lwr upr qty
--------------
900 25000 1000
150 500 450
Above we use {x,y} because in qSQL queries comma does not denote Join.