djang models
1. 創建model
from django.db import models
class Book(models.Model):
title = models.CharField(max_length=50)
2. 創建記錄
# 兩步完成
p = Book(title='Python')
p.save()
# 一步到位
p = Book.objects.create(title='PHP')
3. 更新記錄
p = Book.objects.all()
p[0].title = 'JSP'
p.save()
4. 檢索所有記錄
Book.objects.all()
5. 過濾記錄
Book.objects.filter(title='PHP')
Book.objects.filter(title__contains = 'PH')
Book.objects.filter(attribute__icontains='php')
Book.objects.filter(attribute__statswith='ph')
Book.objects.filter(attribute__endswith='on')
6. 單一檢索
Book.objects.get(attribute=xxx)
注意：
如果返回多條記錄，則拋出錯誤
返回爲空也會報錯
7. 排序
Book.objects.order_by('PHP')
Book.objects.order_by('-JSP')
8. 默認排序
class Book（models.Model):
title = models.CharField(max_lenth=30)
author = models.CharField(max_lenth=50)
class Meta:
ordering = ['title']
9. 鏈式查詢
Book.objects.filter('title').order_by('author')
10. 切片
Book.objects.order_by('title')[0]
Book.objects.order_by('title')[0:2]
# 不支持負數切片
# 但是可以使用此方法
Book.objects.order_by('-title')[0]
11. 一條語句更新多條記錄
Book.objects.all().update(author='Bill Joy' )
12. 刪除對象
p = Book.objects.get(title='JSP')
p.delete
Book.objects.filter(title='PHP').delete()謝謝！