I am trying to group my data by 2 properties, and sum two other properties for each group. My code is off just a bit, because I am getting the same sum for both the fields (value and quantity). What am I missing? Thanks!
The code -
var linq = Enumerable.from(data); var result = linq .groupBy( "{ pCo: $.portCo , sName: $.secName }", "$.value, $.quantity", "{ portCo: $.pCo, security: $.sName, value: $$.sum($.value), quantity: $$.sum($.quantity) }", "$.pCo + ' ' + $.secName") .toArray(); Ok, after n trials and (n-1) errors, got it to work with the following syntax:
var linq = Enumerable.from(data); var result = linq .groupBy( "{ pCo: $.portCo , sName: $.secName }", null, "{ portCo: $.pCo, security: $.sName, value: $$.sum('$.value'), quantity: $$.sum('$.quantity') }", "$.pCo + ' ' + $.secName") .toArray(); The rationale for the null is not clear to me, and i needed '$.x' quotes for the property names in the sum function.
Inspiration for the solution from Jeff's answer here - https://stackoverflow.com/a/15647792/2011729
null when a function is expected will be replaced with the identity function. In this case, you just needed to produce an object that contained a value and quantity property. Your original wasn't a valid expression. Then as you've figured out, you needed to pass in a selector to the sum() function.