php – 如何解决mysqli_fetch_array()错误

参见英文答案 > mysql_fetch_array()/mysql_fetch_assoc()/mysql_fetch_row()/mysql_num_rows etc… expects parameter 1 to be resource or result????????????????????????????????????31个
当我运行页面时它会抛出此错误,但我不知道为什么：

Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result,
boolean given in C:wampwwwSAMSrecord.php on line 234

这是我的查询：

$data = "SELECT *,(SELECT SUM(studAtt_endTime - studAtt_startTime) FROM studentAttendance WHERE studAtt_status='0')
                FROM studentAttendance INNER JOIN student ON studentAttendance.student_stud_matric=student.stud_matric
                INNER JOIN course ON studentAttendance.course_course_code=course.course_code
                WHERE WHERE studentAttendance.course_course_code LIKE '%$_GET[course]%' GROUP BY student_stud_matric;";