解析mysql查詢中的錯誤

Question

這是mysql查詢：

$data = "SELECT course_name, studentAttendance.course_course_code 
FROM login, course, staff, studentAttendance 
WHERE studentAttendance.staff_staff_id = staff.staff_id 
AND studentAttendance.course_course_code = course.course_code 
AND staff.login_login_id = login.login_id 
AND login.login_id = $_SESSION['login_user'] 
GROUP BY studentAttendance.course_course_code";

該錯誤據說是：

Parse error: syntax error, unexpected '' (T_ENCAPSED_AND_WHITESPACE),
expecting identifier (T_STRING) or variable (T_VARIABLE) or number
(T_NUM_STRING) in C:\wamp\www\attendance_system\dashboard-lecturer.php on line 267

Answer 1

在雙引號內使用數組索引變量時，應將變量放在{}內。 因此，請改用{$ _SESSION ['login_user']}。

Answer 2

使用以下查詢，

"SELECT course_name, studentAttendance.course_course_code FROM login, course, staff, studentAttendance 
WHERE studentAttendance.staff_staff_id = staff.staff_id 
AND studentAttendance.course_course_code = course.course_code 
AND staff.login_login_id = login.login_id 
AND login.login_id = '".$_SESSION['login_user']."' 
GROUP BY studentAttendance.course_course_code";

Answer 3

您需要大括號以雙引號字符串訪問數組。 嘗試這個

{$_SESSION['login_user']}