Improve models by fixing labels and adding check constraints

aleksis/apps/lesrooster/migrations/0012_alter_timeboundcourseconfig_lesson_quota_and_more.py

+# Generated by Django 4.2.4 on 2023-09-16 18:43
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("lesrooster", "0011_alter_lesroosterglobalpermissions_options"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="timeboundcourseconfig",
+            name="lesson_quota",
+            field=models.PositiveSmallIntegerField(
+                blank=True,
+                help_text="Number of slots this course is scheduled to fill per week",
+                null=True,
+                verbose_name="Lesson quota",
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name="slot",
+            constraint=models.CheckConstraint(
+                check=models.Q(("time_start__lte", models.F("time_end"))),
+                name="time_start_lte_time_end",
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name="validityrange",
+            constraint=models.CheckConstraint(
+                check=models.Q(("date_start__lte", models.F("date_end"))),
+                name="date_start_lte_date_end",
+            ),
+        ),
+    ]

aleksis/apps/lesrooster/models.py

@@ -4,7 +4,7 @@ from typing import Optional, Union
 
 from django.core.exceptions import ValidationError
 from django.db import models
-from django.db.models import Q, QuerySet
+from django.db.models import F, Q, QuerySet
 from django.utils import timezone
 from django.utils.formats import date_format, time_format
 from django.utils.functional import classproperty
@@ -111,6 +111,9 @@ class ValidityRange(ExtensibleModel):
                 condition=Q(status=ValidityRangeStatus.PUBLISHED),
                 name="lr_unique_dates_per_term",
             ),
+            models.CheckConstraint(
+                check=Q(date_start__lte=F("date_end")), name="date_start_lte_date_end"
+            ),
         ]
         indexes = [
             models.Index(fields=["date_start", "date_end"], name="lr_validity_date_start_end")
@@ -212,6 +215,9 @@ class Slot(ExtensiblePolymorphicModel):
             models.UniqueConstraint(
                 fields=["weekday", "period", "time_grid"], name="lr_unique_period_per_range"
             ),
+            models.CheckConstraint(
+                check=Q(time_start__lte=F("time_end")), name="time_start_lte_time_end"
+            ),
         ]
         ordering = ["weekday", "period"]
         indexes = [models.Index(fields=["time_start", "time_end"])]
@@ -668,7 +674,8 @@ class TimeboundCourseConfig(ExtensibleModel):
     )
 
     lesson_quota = models.PositiveSmallIntegerField(
-        verbose_name=_("Number of slots this course is scheduled to fill per week"),
+        verbose_name=_("Lesson quota"),
+        help_text=_("Number of slots this course is scheduled to fill per week"),
         blank=True,
         null=True,
     )