GlideAggregate COUNT in ServiceNow — How to Count Records Correctly

Counting records in ServiceNow correctly requires understanding GlideAggregate. Using GlideRecord to count records works but is significantly less efficient — GlideRecord loads every matching record into memory before counting. GlideAggregate pushes the COUNT operation to the database and returns only the number.

Basic COUNT

// Count all active incidents
var ga = new GlideAggregate('incident');
ga.addAggregate('COUNT');
ga.addEncodedQuery('active=true');
ga.query();
ga.next();
var count = ga.getAggregate('COUNT');
gs.log('Active incidents: ' + count);
// Output: "Active incidents: 247"

COUNT with groupBy — Counts Per Group

The most useful pattern — count records broken down by a field value:

// Count incidents grouped by priority
var ga = new GlideAggregate('incident');
ga.addAggregate('COUNT');
ga.addEncodedQuery('active=true');
ga.groupBy('priority');
ga.orderBy('priority');
ga.query();

while (ga.next()) {
    var priority = ga.getDisplayValue('priority');
    var count = ga.getAggregate('COUNT');
    gs.log(priority + ': ' + count);
}
// Output:
// "1 - Critical: 3"
// "2 - High: 12"
// "3 - Moderate: 48"

COUNT on a Specific Field

You can count a specific field rather than all rows. This is useful for counting non-null values:

// Count incidents where assigned_to is populated
var ga = new GlideAggregate('incident');
ga.addAggregate('COUNT', 'assigned_to');
ga.addEncodedQuery('active=true');
ga.query();
ga.next();
var assignedCount = ga.getAggregate('COUNT', 'assigned_to');
gs.log('Assigned incidents: ' + assignedCount);

COUNT DISTINCT — Unique Values

// Count how many unique assignment groups have active incidents
var ga = new GlideAggregate('incident');
ga.addAggregate('COUNT DISTINCT', 'assignment_group');
ga.addEncodedQuery('active=true');
ga.query();
ga.next();
var uniqueGroups = ga.getAggregate('COUNT DISTINCT', 'assignment_group');
gs.log('Groups with active incidents: ' + uniqueGroups);

Multiple Aggregates in One Query

// Get count, min, and max in a single database call
var ga = new GlideAggregate('incident');
ga.addAggregate('COUNT');
ga.addAggregate('MIN', 'sys_created_on');
ga.addAggregate('MAX', 'sys_created_on');
ga.addEncodedQuery('active=true^priority=1');
ga.query();

if (ga.next()) {
    gs.log('Count: ' + ga.getAggregate('COUNT'));
    gs.log('Oldest: ' + ga.getAggregate('MIN', 'sys_created_on'));
    gs.log('Newest: ' + ga.getAggregate('MAX', 'sys_created_on'));
}

GlideAggregate vs GlideRecord for Counting

Method	How it works	Performance
GlideAggregate COUNT	Database-level COUNT(*)	Extremely fast — one DB call
GlideRecord + getRowCount()	Loads all matching records	Slow on large tables
GlideRecord loop counter	Iterates every record	Slowest — avoid entirely

On a table with 100,000 records, GlideAggregate COUNT returns in milliseconds. GlideRecord getRowCount() may take several seconds.

Using GlideAggregate in a Script Include

// Reusable function to get record count
function getRecordCount(table, encodedQuery) {
    var ga = new GlideAggregate(table);
    ga.addAggregate('COUNT');
    if (encodedQuery) {
        ga.addEncodedQuery(encodedQuery);
    }
    ga.query();
    if (ga.next()) {
        return parseInt(ga.getAggregate('COUNT'));
    }
    return 0;
}

// Usage
var p1Count = getRecordCount('incident', 'active=true^priority=1');
gs.log('P1 count: ' + p1Count);

Common Mistake — Calling getAggregate Before next()

// ❌ Wrong — getAggregate called before next()
var ga = new GlideAggregate('incident');
ga.addAggregate('COUNT');
ga.query();
var count = ga.getAggregate('COUNT'); // Returns null

// ✅ Correct — always call next() first
var ga = new GlideAggregate('incident');
ga.addAggregate('COUNT');
ga.query();
ga.next(); // Must call this before getAggregate
var count = ga.getAggregate('COUNT'); // Returns the count