As a ServiceNow developer, we should know how to create, Update, Read & Delete Operations in ServiceNow.

To do that we should use ServiceNow GlideRecord Method.

How can you Insert a record in Incident table :

var gr = new GlideRecord('incident');
gr.initialize();
gr.short_description = "Test Insert";
gr.caller_id = "71826bf03710200044e0bfc8bcbe5d3b";
gr.insert();
gs.info('Incident Number '+gr.number+' - '+gr.state.getDisplayValue());

How can you read a record in Incident table :

var gr = new GlideRecord('incident');
if(gr.get('number','INC0010075')){
	gs.info(gr.description+' '+gr.state.getDisplayValue()+' '+gr.assignment_group.getDisplayValue());
}else{
	gs.info('Record Not found');
}

How Can you read list of record in Incident table :

var gr = new GlideRecord('incident');
gr.addEncodedQuery('state=2^priority=2');
//gr.addQuery('state',2); // In Progress Incident
//gr.addQuery('priority',2); 
gr.query();
gs.info('Record Count '+gr.getRowCount());
while(gr.next()){
	gs.info(gr.number+' '+gr.short_description);
}

Youtube Link: https://youtu.be/mssfoXfIe0I