_assign field info

how to get the value of _assign field ??

Try with

frappe.db.get_value(‘Purchase Order’, doc.name,“_assign”)

for Purchase Order doctype, I think should work with other doctype also

this will give you the answer :

frappe.db.get_value(‘Issue’, frm.doc.name,‘_assign’, function(value) {
console.log(value);
});

Yes in client side, server and client side api call looks identical.