The Course Performance Brief

The UniLearn registrar needs a course performance report for a fictional 2026 semester. Summarise active enrolments, including students whose scores are not yet available.

Prepare Your PostgreSQL Data

Open your practice database in pgAdmin Query Tool. Turn Auto-commit on.
Choose Open File and select the separately supplied lab5_setup.sql.
Execute the whole file. It selects the lab5 schema. In the same Query Tool, copy the inspection query from Code and confirm 36 rows.

What Does One Row Mean?

One row is one student's enrolment in one course. S101 takes three courses, so S101 appears three times. An enrolment count and a student count can differ.

Build the Registrar's Report

Count enrolments, recorded scores, and distinct students.
Calculate totals and averages for each course.
Keep courses that meet the requested summary conditions.

💡 Read Before Summarising

NULL means no recorded score; 0 is a recorded score. Withdrawn enrolments remain in the table but are excluded from the report.

Preview: First 12 of 36 Enrolments

The full enrolments table contains 20 distinct students across six courses. Six withdrawn rows will be filtered out of the report. Run the inspection query to see all 36 rows.

Enrolment	Student	Programme	Course	Status	Score	Hours
E01	S101	DSAI	SQL101	active	80	6
E02	S102	CS	SQL101	active	60	4
E03	S103	DSAI	SQL101	active	NULL	5
E04	S104	IT	SQL101	withdrawn	90	2
E05	S101	DSAI	PY101	active	90	8
E06	S105	CS	PY101	active	50	6
E07	S106	DSAI	PY101	active	70	7
E08	S107	IT	PY101	active	NULL	3
E09	S102	CS	VIS101	active	40	4
E10	S108	DSAI	VIS101	active	NULL	2
E11	S109	IT	VIS101	withdrawn	100	1
E12	S110	IT	VIS101	active	0	1

Read the Columns

enrolment_id identifies one enrolment; student_id may repeat.
score is a mark out of 100, or NULL if unrecorded.
study_hours records hours for this enrolment.

💡 PostgreSQL Syntax

Text values use single quotes. Numbers and SQL NULL do not. End each statement with a semicolon.

SET search_path TO lab5;

SELECT *
FROM enrolments
ORDER BY enrolment_id;

New Query Tool or Reconnected?

The setup selects the schema for its current connection. Run the following once in a new connection, then use the lesson queries normally.

SET search_path TO lab5;