fix: mtm cate默认为空字符串

apps/mtm/migrations/0022_alter_material_cate.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.12 on 2023-11-01 02:53
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mtm', '0021_material_brothers'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='material',
+            name='cate',
+            field=models.CharField(blank=True, default='', max_length=20, verbose_name='大类'),
+        ),
+    ]

apps/mtm/models.py

@@ -43,7 +43,7 @@ class Material(CommonAModel):
     )
 
     name = models.CharField('名称', max_length=50)
-    cate = models.CharField('大类', max_length=20, default='')
+    cate = models.CharField('大类', max_length=20, default='', blank=True)
     number = models.CharField('编号', max_length=100, null=True, blank=True)
     specification = models.CharField(
         '型号', max_length=100, null=True, blank=True)