diff --git a/main/inc/lib/course.lib.php b/main/inc/lib/course.lib.php
index 994bdb84e6..da39956276 100644
--- a/main/inc/lib/course.lib.php
+++ b/main/inc/lib/course.lib.php
@@ -2157,7 +2157,7 @@ class CourseManager {
 	   	$tbl_course_rel_user 	= Database::get_main_table(TABLE_MAIN_COURSE_USER);
 	   	$tbl_user				= Database::get_main_table(TABLE_MAIN_USER);
 	
-	   	$sql = "SELECT course_code FROM $tbl_course_rel_user WHERE id_user = $user_id AND relation_type = 1 ";
+	    $sql = "SELECT course_code FROM $tbl_course_rel_user WHERE user_id = $user_id AND relation_type = 1 ";
 		$result = Database::query($sql,__FILE__,__LINE__);
 		$existing_courses = array();
 		while($row = Database::fetch_array($result)){
@@ -2167,7 +2167,7 @@ class CourseManager {
 		//Deleting existing session_rel_user with relation ship = 1 only 
 		foreach ($existing_courses as $existing_course) {		
 			$existing_course = Database::escape_string($existing_course);	
-			$sql = "DELETE FROM $tbl_course_rel_user WHERE course_code = $existing_course  AND id_user=$user_id AND relation_type = 1 ";
+			$sql = "DELETE FROM $tbl_course_rel_user WHERE course_code = '$existing_course'  AND user_id = $user_id AND relation_type = 1 ";
 			Database::query($sql,__FILE__,__LINE__);					
 		}
 
@@ -2175,6 +2175,7 @@ class CourseManager {
 			// for each session		
             $course_code = Database::escape_string($course_code);
 			$insert_sql = "INSERT IGNORE INTO $tbl_course_rel_user(course_code,user_id,relation_type) VALUES('$course_code','$user_id','1')";
+			
 			Database::query($insert_sql,__FILE__,__LINE__);
 		}
 	}