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Discover how to accurately count only active students in a class in your CodeIgniter application, using effective MySQL queries.
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This video is based on the question https://stackoverflow.com/q/67925172/ asked by the user 'Mary4bills' ( https://stackoverflow.com/u/14833134/ ) and on the answer https://stackoverflow.com/a/67925529/ provided by the user 'Kinglish' ( https://stackoverflow.com/u/1772933/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Get the Total Number of Active Students in CodeIgniter Using MySQL

When working with student management systems, accurately counting the number of active students is crucial. However, if your database includes inactive or disabled students, the challenge arises in distinguishing between active and inactive records. In this guide, we'll dive into an example using two key tables (students and student_session) and demonstrate how to write an effective query that ensures you only count active students.

Understanding the Database Structure

Before we proceed with the solution, let's review the relevant tables that store our student data.

Students Table Structure

The students table holds essential information about each student. Here is a simplified view of its structure:

[[See Video to Reveal this Text or Code Snippet]]

Student Session Table Structure

The student_session table associates students with their particular classes and tracks their status.

[[See Video to Reveal this Text or Code Snippet]]

Key Note: In the students table, the is_active column indicates a student's status. The value 'yes' signifies an active student, while 'no' references a disabled student.

The Challenge

As described, the initial approach to counting students:

[[See Video to Reveal this Text or Code Snippet]]

This code counts all students in a session, but it does not filter out disabled students. Consequently, the count may include students who are marked inactive.

The Solution

To accurately get the count of active students, you can enhance the query by leveraging a JOIN to access the is_active status in the students table. Here’s how you can do it:

Improved Query Using JOIN

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of the Query

Count Active Students: We are selecting the count of student IDs as total, ensuring that we only count those who are marked as active (is_active = 'yes').

Join Tables: This query uses a join between the student_session table (ss) and the students table (st) to access both the session data and the active status of each student.

Where Clause: We filter by session ID, section ID, and class ID, ensuring the criteria match your needs.

Conclusion

By implementing this improved SQL query, you can effectively count the total number of active students in a specified session and class. This solution helps maintain the integrity of your student data, ensuring that inactive students do not skew your results. Remember to test various cases to ensure your application behaves as expected.

Now you can easily integrate this solution into your CodeIgniter application and handle your student management with confidence. Happy coding!