GlideRecord the sums fields value of multiple records

[kenpeck]

We have built an app called recognition toolkit. Toolkits consist of gift cards that are issued to managers who then gift the cards to employees for good work. What I want to do is after any card is issued from a toolkit I want the script to loop thru the toolkits inventory, summing the card_count field. If they all equal 0 then I will automatically close the toolkit and notify HR.

I'm already doing something similar. When a toolkit is recalled for any reason the following script runs closes the toolkit and puts all of the remaining toolkit inventory back into the main inventory. Works great. I just can't figure out how to loop thru the card counts keeping a running total. Any help would be appreciated

current.state = 500;
current.closed_at = gs.nowDateTime();
current.closed_by = gs.getUserID();
current.update();
gs.addInfoMessage('Toolkit Recalled');
action.setRedirectURL(current);  

var mtc = current.sys_id;
var gr = new GlideRecord('u_manager_toolkit_inventory');
gr.addQuery('u_mtc_number', mtc);
gr.query();
while(gr.next()){
	var current_cnt = gr.u_card_count;
	var card_type = gr.u_card_type;
	
	//Add card count back to card type inventory
	var grCT = new GlideRecord('u_card_type');
	grCT.addQuery('sys_id', card_type);
	grCT.query();
	if(grCT.next()){
		grCT.u_card_count = grCT.u_card_count + current_cnt;
		grCT.update();
	}
	gr.u_card_count = 0;
	gr.update();
	
}

[Shane J]

Here's an example BR script (on the child record table) I use to add up hours to a parent in a custom table I have related to Project.  You can probably follow what it's doing to build your own.

(function executeRule(current, previous /*null when async*/) {
var prj = new GlideRecord('u_project_scope_change_request');
prj.addQuery('sys_id', current.u_parent);
prj.query();
while(prj.next()){
var tc = new GlideRecord('u_project_scope_change_financials');
tc.addQuery("u_parent", prj.sys_id);
var fy1Sum = 0;
var fy2Sum = 0;
tc.query();
while (tc.next()) {
fy1Sum += tc.u_total_capex;
fy2Sum += tc.u_total_opex;
}
prj.u_total_capex = fy1Sum;
prj.u_total_opex = fy2Sum;
prj.update();

}

})(current, previous);