How to Resolve MySQL's EXCEPT Syntax Error and Find Alternatives?

MySQL EXCEPT Syntax Error: Resolution and Alternatives

The error encountered while attempting to execute the query with the EXCEPT operator in MySQL arises due to its lack of support for this syntax.

To overcome this issue, consider utilizing alternative approaches like NOT IN or a LEFT JOIN:

SELECT s.sno 
FROM students s
WHERE s.sno NOT IN 
(
    SELECT t.sno 
    FROM take t 
    WHERE t.cno = 'CS112'
);

Alternatively, you can employ a LEFT JOIN:

SELECT s.sno 
FROM students s
    LEFT JOIN take t ON s.sno = t.sno
WHERE IFNULL(t.cno, '') != 'CS112'

Demonstration with Temporary Tables:

To illustrate the effectiveness of these alternatives, let us create temporary tables with sample data:

create temporary table temp_students (sno int)

insert into temp_students values (1)
insert into temp_students values (2)
insert into temp_students values (3)
insert into temp_students values (4)
insert into temp_students values (5)
insert into temp_students values (6)
insert into temp_students values (7)
insert into temp_students values (8)
insert into temp_students values (9)
insert into temp_students values (10)

create temporary table temp_take (sno int, cno varchar(50))

insert into temp_take values (1, 'CS112')
insert into temp_take values (2, 'CS112')
insert into temp_take values (3, 'CS112')
insert into temp_take values (4, 'CS112')

Execute the following query to retrieve students who are not enrolled in CS112:

SELECT s.sno 
FROM temp_students s
        LEFT JOIN temp_take t ON s.sno = t.sno
WHERE IFNULL(t.cno, '') != 'CS112'

This query should return the student numbers 5 through 10.

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