Day 3 のデータモデル実装が完了しました。

完了内容
models.py
fields/models.py:
- OfficialKyosaiField - 共済マスタ
- OfficialChusankanField - 中山間マスタ
- Field - 圃場（PointField で位置情報対応）
plans/models.py:
- Crop - 作物マスタ
- Variety - 品種マスタ（unique_together 制約）
- Plan - 作付け計画（unique_together 制約）
admin.py
- 全てのモデルを admin に登録
- list_display, search_fields, list_filter 設定
- FieldAdmin は GIS 用 GISModelAdmin を使用
マイグレーション
✅ makemigrations - 成功
✅ migrate - 成功
管理画面 (http://localhost:8000/admin) で全てのモデルが確認・編集できます。

backend/apps/plans/migrations/0001_initial.py

@@ -0,0 +1,57 @@
+# Generated by Django 5.0 on 2026-02-15 02:45
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ('fields', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Crop',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=100, unique=True, verbose_name='作物名')),
+            ],
+            options={
+                'verbose_name': '作物マスタ',
+                'verbose_name_plural': '作物マスタ',
+            },
+        ),
+        migrations.CreateModel(
+            name='Variety',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=100, verbose_name='品種名')),
+                ('crop', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='varieties', to='plans.crop', verbose_name='作物')),
+            ],
+            options={
+                'verbose_name': '品種マスタ',
+                'verbose_name_plural': '品種マスタ',
+                'unique_together': {('crop', 'name')},
+            },
+        ),
+        migrations.CreateModel(
+            name='Plan',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('year', models.IntegerField(verbose_name='作付年度')),
+                ('notes', models.TextField(blank=True, null=True, verbose_name='備考')),
+                ('crop', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='plans', to='plans.crop', verbose_name='作物')),
+                ('field', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='plans', to='fields.field', verbose_name='圃場')),
+                ('variety', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='plans', to='plans.variety', verbose_name='品種')),
+            ],
+            options={
+                'verbose_name': '作付け計画',
+                'verbose_name_plural': '作付け計画',
+                'ordering': ['-year', 'field'],
+                'unique_together': {('field', 'year')},
+            },
+        ),
+    ]