Auto-Generate Student Roll Number using Apex

Project Overview:

This project automates the generation of unique roll numbers for students in Salesforce. When a new student is admitted, their roll number is automatically generated based on their Class and Admission Year. This eliminates manual errors and ensures unique identification.

Objectives:

– Automate roll number assignment.
– Ensure uniqueness across students.
– Generate roll numbers in a standard format.
– Reduce manual data entry effort.

System Design:

Student__c (Custom Object)

• Name → Student Name (Standard)
• Class__c → Class (Picklist: BCA, BBA, MCA)
• Admission_Date__c → Admission Date (Date)
• Roll_Number__c → Roll Number (Text, Auto-generated, Read-Only)

Roll Number Format

Format: Class-Year-Sequence
Example:
– First Student in BCA 2025 → BCA-2025-1
– Second Student in BCA 2025 → BCA-2025-2
– First Student in BBA 2025 → BBA-2025-1

Implementation:

Apex Trigger

trigger AutoGenerateRollNumber on Student__c (before insert) {
    Map<String, Integer> maxNumbersMap = new Map<String, Integer>();

    for (Student__c stu : Trigger.new) {
        if (stu.Class__c != null && stu.Admission_Date__c != null) {
            String year = String.valueOf(stu.Admission_Date__c.year());
            String key = stu.Class__c + ‘-‘ + year;
            maxNumbersMap.put(key, 0);
        }
    }

    List<Student__c> existingStudents = [
        SELECT Roll_Number__c FROM Student__c
        WHERE Roll_Number__c != NULL
    ];

    for (Student__c s : existingStudents) {
        String[] parts = s.Roll_Number__c.split(‘-‘);
        if (parts.size() == 3) {
            String key = parts[0] + ‘-‘ + parts[1];
            Integer seq = Integer.valueOf(parts[2]);
            if (maxNumbersMap.containsKey(key) && seq > maxNumbersMap.get(key)) {
                maxNumbersMap.put(key, seq);
            }
        }
    }

    for (Student__c stu : Trigger.new) {
        if (stu.Class__c != null && stu.Admission_Date__c != null) {
            String year = String.valueOf(stu.Admission_Date__c.year());
            String key = stu.Class__c + ‘-‘ + year;
            Integer nextNum = maxNumbersMap.get(key) + 1;
            stu.Roll_Number__c = key + ‘-‘ + nextNum;
            maxNumbersMap.put(key, nextNum);
        }
    }
}

Example Execution:

Student Name	Class	Admission Date	Roll Number (Auto)
Shoeb	BCA	2025-08-28	BCA-2025-1
Amir	BCA	2025-09-02	BCA-2025-2
Sana	BBA	2025-08-30	BBA-2025-1

Benefits:

– Automated roll number generation.
– No duplicates within same Class-Year.
– Scalable for multiple classes and years.
– Error-free roll number assignment.

Limitations:

– Bulk insert of more than 200 students may hit SOQL governor limits.
– Possible concurrency issues if many users add students at the same time.

Auto Roll_number generator