Question

In SQL, you have a table 'Students' with columns 'StudentID', 'StudentName', and 'CollegeID', and a table 'Colleges' with the columns 'CollegeID' and 'CollegeName'.

You have been asked to obtain a list of all students and the names of their respective colleges. In the case that the name of a student's college cannot be found in the database, you are still required to retrieve the student's information.

Which of the following operations is MOST relevant in the case?

Answer 1

A left join operation in SQL is used to retrieve all student records along with their college names, showing NULL for college names not found in the database.

Step-by-step explanation:

To retrieve a list of all students and the names of their respective colleges, even if the college name is not available, you need to perform a left join operation in SQL. This will return all records from the left table (Students), and the matched records from the right table (Colleges), with NULL in the result if there is no match. Here's an example query:

SELECT Students.StudentID, Students.StudentName, Colleges.CollegeName
FROM Students
LEFT JOIN Colleges
ON Students.CollegeID = Colleges.CollegeID;

This query will give you all the student IDs, student names, and college names. For students whose colleges aren't in the database, the CollegeName will appear as NULL.