在mysql查询中解析错误

Question

这是mysql查询：

$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";

错误据说是：

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

在双引号内使用数组索引变量时，应将变量放在{}中。所以请改用{$ _SESSION ['login_user']}。

Answer 2

使用以下查询

"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

在双引号字符串中，您需要使用大括号进行数组访问。 试试这个

{$_SESSION['login_user']}