Django এর Meta ক্লাসে বিভিন্ন মেটাডাটা কনফিগার

class MyModel(models.Model):
    field1 = models.CharField(max_length=100)

    class Meta:
        db_table = 'my_custom_table_name'

class MyModel(models.Model):
    name = models.CharField(max_length=100)

    class Meta:
        ordering = ['name']  # 'name' ফিল্ড অনুযায়ী অর্ডার হবে

class MyModel(models.Model):
    name = models.CharField(max_length=100)

    class Meta:
        verbose_name = 'My Model'  # Django অ্যাডমিনে মডেলের নাম এইভাবে দেখাবে

class MyModel(models.Model):
    name = models.CharField(max_length=100)

    class Meta:
        verbose_name_plural = 'My Models'

class MyModel(models.Model):
    name = models.CharField(max_length=100)
    salary = models.DecimalField(max_digits=10, decimal_places=2)

    class Meta:
        constraints = [
            models.CheckConstraint(check=models.Q(salary__gte=0), name='salary_gte_0')
        ]

from django.db.models import Index

class MyModel(models.Model):
    field1 = models.CharField(max_length=100)
    field2 = models.CharField(max_length=100)

    class Meta:
        indexes = [
            Index(fields=['field1', 'field2'])
        ]

class MyModel(models.Model):
    name = models.CharField(max_length=100)

    class Meta:
        default_permissions = ('add', 'change')  # কেবলমাত্র add এবং change পারমিশন থাকবে

class MyModel(models.Model):
    name = models.CharField(max_length=100)

    class Meta:
        permissions = [
            ('can_publish', 'Can Publish'),
            ('can_archive', 'Can Archive'),
        ]

class MyModel(models.Model):
    name = models.CharField(max_length=100)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        get_latest_by = 'created_at'

class MyModel(models.Model):
    name = models.CharField(max_length=100)

    class Meta:
        managed = False  # Django টেবিল তৈরি করবে না

class MyModel(models.Model):
    name = models.CharField(max_length=100)

    class Meta:
        select_on_save = True  # সেভ করার আগে রেকর্ড সিলেক্ট করবে

class MyModel(models.Model):
    name = models.CharField(max_length=100)

    class Meta:
        app_label = 'my_app'  # মডেলটি কোন অ্যাপের অন্তর্ভুক্ত তা নির্ধারণ

from django.db import models

class BlogPost(models.Model):
    title = models.CharField(max_length=255)
    content = models.TextField()
    pub_date = models.DateField()

    # This title must be unique for the same date
    title.unique_for_date = pub_date

    # This title must be unique for the same month
    title.unique_for_month = pub_date

    # This title must be unique for the same year
    title.unique_for_year = pub_date

    def __str__(self):
        return self.title

from django import forms
from .models import BlogPost

class BlogPostForm(forms.ModelForm):
    class Meta:
        model = BlogPost
        fields = ['title', 'content', 'pub_date']

    def clean(self):
        cleaned_data = super().clean()
        title = cleaned_data.get('title')
        pub_date = cleaned_data.get('pub_date')

        # Ensure unique_for_date is respected
        if BlogPost.objects.filter(title=title, pub_date=pub_date).exists():
            raise forms.ValidationError("The title must be unique for the same date.")

        return cleaned_data

from django.test import TestCase
from .models import BlogPost

class BlogPostTestCase(TestCase):
    def setUp(self):
        BlogPost.objects.create(title='My Unique Post', content='Test Content', pub_date='2023-10-01')

    def test_unique_title_for_date(self):
        # Trying to create a post with the same title on the same date should fail
        with self.assertRaises(Exception):
            BlogPost.objects.create(title='My Unique Post', content='Another Test', pub_date='2023-10-01')

    def test_unique_title_for_month(self):
        # Creating a post with the same title but different date in the same month should fail
        with self.assertRaises(Exception):
            BlogPost.objects.create(title='My Unique Post', content='Another Test', pub_date='2023-10-15')

    def test_unique_title_for_year(self):
        # Creating a post with the same title but different date in the same year should fail
        with self.assertRaises(Exception):
            BlogPost.objects.create(title='My Unique Post', content='Another Test', pub_date='2023-12-01')