fix: added unique_together constraint on learner pathway course and

program models

course_discovery/apps/learner_pathway/admin.py

@@ -16,7 +16,6 @@ class LearnerPathwayProgramInline(admin.TabularInline):
     model = LearnerPathwayProgram
     extra = 0
     autocomplete_fields = ('program', )
-    classes = ('collapse',)
     readonly_fields = ('estimated_completion_time',)
 
     def estimated_completion_time(self, pathway_program):
@@ -27,7 +26,6 @@ class LearnerPathwayCourseInline(admin.TabularInline):
     model = LearnerPathwayCourse
     extra = 0
     autocomplete_fields = ('course', )
-    classes = ('collapse',)
     readonly_fields = ('estimated_completion_time',)
 
     def estimated_completion_time(self, pathway_course):

course_discovery/apps/learner_pathway/migrations/0004_auto_20220119_1338.py

@@ -0,0 +1,22 @@
+# Generated by Django 3.2.10 on 2022-01-19 13:38
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('course_metadata', '0267_remove_course_slug'),
+        ('learner_pathway', '0003_auto_20220119_0726'),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name='learnerpathwaycourse',
+            unique_together={('step', 'course')},
+        ),
+        migrations.AlterUniqueTogether(
+            name='learnerpathwayprogram',
+            unique_together={('step', 'program')},
+        ),
+    ]

course_discovery/apps/learner_pathway/models.py

@@ -197,6 +197,11 @@ class LearnerPathwayCourse(LearnerPathwayNode):
 
     course = models.ForeignKey(Course, on_delete=models.CASCADE, related_name='learner_pathway_courses')
 
+    class Meta:
+        unique_together = (
+            ('step', 'course'),
+        )
+
     def get_estimated_time_of_completion(self) -> str:
         """
         Returns the average estimated work hours to complete the course run.
@@ -230,6 +235,11 @@ class LearnerPathwayProgram(LearnerPathwayNode):
 
     program = models.ForeignKey(Program, on_delete=models.CASCADE, related_name='learner_pathway_programs')
 
+    class Meta:
+        unique_together = (
+            ('step', 'program'),
+        )
+
     def get_estimated_time_of_completion(self) -> str:
         """
         Returns the sum of estimated work hours to complete the course run for all program courses.