Student Management System in Go with Source Code

Let's create a basic Student Management System in Go (also known as Golang) that provides functionalities for CRUD (create student, read student, update student, and delete student) operations.

Source Code: Student Management System in Golang

package main

import (
	"fmt"
)

type Student struct {
	RollNo int
	Name   string
	Marks  float64
}

var students = make(map[int]Student)

func addStudent(rollNo int, name string, marks float64) {
	students[rollNo] = Student{RollNo: rollNo, Name: name, Marks: marks}
}

func displayStudents() {
	for _, student := range students {
		fmt.Printf("Roll No: %d, Name: %s, Marks: %f\n", student.RollNo, student.Name, student.Marks)
	}
}

func updateStudent(rollNo int, name string, marks float64) {
	if _, exists := students[rollNo]; exists {
		students[rollNo] = Student{RollNo: rollNo, Name: name, Marks: marks}
	} else {
		fmt.Println("Student not found!")
	}
}

func deleteStudent(rollNo int) {
	if _, exists := students[rollNo]; exists {
		delete(students, rollNo)
	} else {
		fmt.Println("Student not found!")
	}
}

func main() {
	var choice, rollNo int
	var name string
	var marks float64

	for {
		fmt.Println("\n1. Add Student\n2. Display Students\n3. Update Student\n4. Delete Student\n5. Exit")
		fmt.Print("Enter your choice: ")
		fmt.Scan(&choice)

		switch choice {
		case 1:
			fmt.Print("Enter roll number, name, and marks: ")
			fmt.Scan(&rollNo, &name, &marks)
			addStudent(rollNo, name, marks)
		case 2:
			displayStudents()
		case 3:
			fmt.Print("Enter roll number to update: ")
			fmt.Scan(&rollNo)
			fmt.Print("Enter new name and marks: ")
			fmt.Scan(&name, &marks)
			updateStudent(rollNo, name, marks)
		case 4:
			fmt.Print("Enter roll number to delete: ")
			fmt.Scan(&rollNo)
			deleteStudent(rollNo)
		case 5:
			return
		}
	}
}

Explanation: 

We define a Student struct that will hold each student's details. We utilize a map called students where the key is the roll number (unique for each student) and the value is a Student struct.

Functions addStudent, displayStudents, updateStudent, and deleteStudent implement the CRUD functionalities. 

In the main() function, we have a loop to provide a menu-driven approach for the user to interact with the system. 

Output: 

When executed, the program will show a menu, allowing the user to: 

1. Add a student by inputting roll number, name, and marks.
2. Display all students' details.
3. Update a student's name and marks using the roll number.
4. Delete a student using the roll number.
5. Exit the application. 

Upon each operation, the user will be redirected back to the main menu until they decide to exit. 

Here is the complete output:

1. Add Student
2. Display Students
3. Update Student
4. Delete Student
5. Exit
Enter your choice: 1
Enter roll number, name, and marks: 100 John 50
1. Add Student
2. Display Students
3. Update Student
4. Delete Student
5. Exit
Enter your choice: 2
Roll No: 100, Name: John, Marks: 50.000000

1. Add Student
2. Display Students
3. Update Student
4. Delete Student
5. Exit
Enter your choice: 3
Enter roll number to update: 100
Enter new name and marks: Tom 80
1. Add Student
2. Display Students
3. Update Student
4. Delete Student
5. Exit
Enter your choice: 4
Enter roll number to delete: 100
1. Add Student
2. Display Students
3. Update Student
4. Delete Student
5. Exit
Enter your choice: 5

This Student Management System provides a simple example of CRUD operations in Go. Adjustments and enhancements can be made based on your specific requirements.

Happy Coding!.