SQL Select-tekenreeks werkt niet

Uw vraag is onjuist:probeer dit

SELECT Comment1, Comment2, Comment3, Comment4 
FROM Students 
WHERE Course1 = '$value1' AND Course2 = '$value1' 
AND Course3 = '$value1' AND Course4 = '$value1'

OF

SELECT Comment1, Comment2, Comment3, Comment4 
FROM Students 
WHERE Course1 = '$value1' OR Course2 = '$value1' 
OR Course3 = '$value1' OR Course4 = '$value1'

Gebruik AND of OR op basis van uw vereisten tijdens het controleren van de cursus