Fix teachers can't subscribe to Session from Course and some minor code fixing

main/cron/import_csv.php

@@ -1385,7 +1385,7 @@ class ImportCsv
                         SessionManager::set_coach_to_course_session(
                             $userId,
                             $chamiloSessionId,
-                            $courseInfo['code']
+                            $courseInfo['real_id']
                         );
                         break;
                 }

main/inc/lib/sessionmanager.lib.php

@@ -2785,9 +2785,9 @@ class SessionManager
                     // and then exit
                     $sql = "DELETE FROM $tbl_session_rel_course_rel_user
                             WHERE
-                                session_id = '$session_id' AND
-                                c_id = '$courseId' AND
-                                user_id = '$user_id' ";
+                                session_id = $session_id AND
+                                c_id = $courseId AND
+                                user_id = $user_id ";
                     $result = Database::query($sql);
                     if (Database::affected_rows($result) > 0)
                         return true;
@@ -2799,18 +2799,18 @@ class SessionManager
                 // First check if the user is registered to the course
                 $sql = "SELECT user_id FROM $tbl_session_rel_course_rel_user
                         WHERE
-                            session_id = '$session_id' AND
-                            c_id = '$courseId' AND
-                            user_id = '$user_id'";
+                            session_id = $session_id AND
+                            c_id = $courseId AND
+                            user_id = $user_id";
                 $rs_check = Database::query($sql);
 
                 // Then update or insert.
                 if (Database::num_rows($rs_check) > 0) {
                     $sql = "UPDATE $tbl_session_rel_course_rel_user SET status = 2
 					        WHERE
-					            session_id = '$session_id' AND
-					            c_id = '$courseId' AND
-					            user_id = '$user_id' ";
+					            session_id = $session_id AND
+					            c_id = $courseId AND
+					            user_id = $user_id ";
                     $result = Database::query($sql);
                     if (Database::affected_rows($result) > 0) {
                         return true;
@@ -2819,7 +2819,7 @@ class SessionManager
                     }
                 } else {
                     $sql = "INSERT INTO $tbl_session_rel_course_rel_user(session_id, c_id, user_id, status)
-                            VALUES('$session_id', '$courseId', '$user_id', 2)";
+                            VALUES($session_id, $courseId, $user_id, 2)";
                     $result = Database::query($sql);
                     if (Database::affected_rows($result) > 0) {
                         return true;

main/user/subscribe_user.php

@@ -60,7 +60,7 @@ if (isset($_REQUEST['register'])) {
             $result_simple_sub = SessionManager::set_coach_to_course_session(
                 $_REQUEST['user_id'],
                 $current_session_id,
-                $courseInfo['code']
+                $courseInfo['real_id']
             );
         } else {
             $result_simple_sub = CourseManager:: subscribe_user(
@@ -109,7 +109,7 @@ if (isset($_POST['action'])) {
                             $is_suscribe[] = SessionManager::set_coach_to_course_session(
                                 $user_id,
                                 $current_session_id,
-                                $courseInfo['code']
+                                $courseInfo['real_id']
                             );
                         } else {
                             $is_suscribe[] = CourseManager::subscribe_user(