修改演示数据插入脚本

src/Jiaowu.Api/Infrastructure/Persistence/DemoDataSeeder.cs

@@ -457,16 +457,18 @@ public sealed class DemoDataSeeder(
             .Select(x => (x.TeacherId, x.CourseId))
             .ToHashSet();
         var additions = new List<TeacherCourseApplication>();
-        for (var teacherIndex = 0; teacherIndex < teachers.Count; teacherIndex++)
+        foreach (var teacher in teachers)
         {
-            var teacher = teachers[teacherIndex];
             var professionalCourses = courses
                 .Where(x => x.CollegeId == teacher.CollegeId &&
-                            x.Nature is CourseNature.MajorRequired or
-                                CourseNature.MajorElective or CourseNature.Practice)
+                            x.Nature is (CourseNature.MajorRequired or
+                                CourseNature.MajorElective or CourseNature.Practice))
                 .Take(4);
-            var selectedPublicCourses = Enumerable.Range(0, 2)
-                .Select(offset => publicCourses[(teacherIndex + offset) % publicCourses.Count]);
+            var collegePublicCourses = publicCourses
+                .Where(x => x.CollegeId == teacher.CollegeId)
+                .ToList();
+            var selectedPublicCourses = collegePublicCourses
+                .Take(2);
             foreach (var course in professionalCourses
                          .Concat(selectedPublicCourses)
                          .DistinctBy(x => x.Id))