Hi Zhen - you'll have to run a server-side script like the examples below; where you run the script is up to the requirement and it may be in Business Rules, Scheduled Jobs, etc. Can you describe exactly what you're trying to achieve?
// first get the row count
// for row count, use GlideAggregate instead of GlideRecord
// http://wiki.servicenow.com?title=GlideAggregate
var cmdb = new GlideAggregate('cmdb_ci'); // use the table name of the CI type you want
cmdb.addAggregate('COUNT');
cmdb.query();
var count = 0;
if (cmdb.next()) count = cmdb.getAggregate('COUNT');
// insert the row count to table xyz, column count
// http://wiki.servicenow.com?title=GlideRecord#Insert_Methods
var gr = new GlideRecord('xyz');
gr.initialize();
gr.count = count;
gr.insert();
// or update existing record's column count in table xyz
// http://wiki.servicenow.com?title=GlideRecord#Update_Methods
var gr = new GlideRecord('xyz');
gr.addQuery(); // add a query to filter the row(s) to update
gr.query(); // this may return 0 or more records
while (gr.next()) { // update all records
gr.count = count;
gr.update();
}
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John Chun, PhD PMP 
So I did a sample business rule and wanted to insert a value of 2 into a field every time a user displayed my table: u_sample_zz_table
I put the condition as onDisplay assuming that every time a user displays the table, a value of 2 will be inserted into the table column: u_integer_2
I used the following script:
var sampleData = new GlideRecord("u_sample_zz_table");
sampleData.initialize();
sampleData.u_integer_2 = 2;
sampleData.insert();
I have attached a screenshot of the fields. Am I missing something in my logic of this process?
Please let me know!!
