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Databases SQL Reporting by Example Day 3: Getting Good at Grouping Janis' Schedule

Tommy Gebru
Tommy Gebru
30,164 Points
Posted by Tommy Gebru
Tommy Gebru
30,164 Points

Solution: JANIS Schedule

-- What class does Janis Ambrose teach during each period? Be sure to include all 7 periods in your report!

The teachers walkthrough solution which returns an error:

WITH JANIS_SCHEDULE AS (
SELECT PERIOD_ID, CLASSES.SUBJECT_ID FROM TEACHERS
JOIN CLASSES ON TEACHERS.ID = CLASSES.TEACHER_ID
JOIN SUBJECTS ON SUBJECTS.ID = CLASSES.SUBJECT_ID
WHERE TEACHERS.ID = 391)
SELECT PERIODS.ID, JANIS_SCHEDULE.NAME FROM PERIODS
LEFT OUTER JOIN JANIS_SCHEDULE
ON PERIODS.ID = PERIOD_ID;

I played around with it some more and this is the line where the error is coming from

SELECT PERIODS.ID, JANIS_SCHEUDLE.NAME FROM PERIODS

instead the solution is

SELECT PERIODS.ID,  NAME FROM PERIODS

:point_up: also this will display a solution too :point_down:

SELECT ID,  NAME FROM PERIODS

no errors and solution is displayed when you omit the temporary table name :smile: :smile:

1 Answer

Tommy Gebru
Tommy Gebru
30,164 Points
Tommy Gebru
Tommy Gebru
30,164 Points

ALSO there is another quick solution provided by Steven Parker without using the CTE or common table expression:

SELECT PERIODS.ID, SUBJECTS.NAME
FROM PERIODS 
LEFT JOIN CLASSES 
ON PERIODS.ID = PERIOD_ID AND TEACHER_ID = 391
LEFT JOIN SUBJECTS 
ON SUBJECTS.ID = SUBJECT_ID