// Create a GlideRecord for the 'cmdb_ci' table
var cmdbCiGr = new GlideRecord('cmdb_ci');
cmdbCiGr.addEncodedQuery('sys_class_name=cmdb_ci_computer^serial_numberISNOTEMPTY^assetISEMPTY');
cmdbCiGr.query();

// Create a GlideRecord for the 'alm_asset' table
var almAssetGr = new GlideRecord('alm_asset');
almAssetGr.addEncodedQuery('ci=NULL^serial_numberISNOTEMPTY');
almAssetGr.query();

// Loop through 'alm_asset' records and check for matching serial numbers in 'cmdb_ci'
while (almAssetGr.next()) {
    var serialNumber = almAssetGr.serial_number;

    // Create a new GlideRecord for 'cmdb_ci' and query based on serial number
    var cmdbCiGrBySerial = new GlideRecord('cmdb_ci');
    cmdbCiGrBySerial.addQuery('serial_number', serialNumber);
    cmdbCiGrBySerial.query();

    if (cmdbCiGrBySerial.next()) {
        // Do something with the matching records
        gs.log('Match found: ' + serialNumber);
    }
}