一, F Q
# F 使用查询条件的值
#
# from django.db.models import F
# models.Tb1.objects.update(num=F('num')+1) # Q 构建搜索条件
from django.db.models import Q
# con = Q()
#
# q1 = Q()
# q1.connector = 'OR'
# q1.children.append(('id', 1))
# q1.children.append(('id', 10))
# q1.children.append(('id', 9))
#
# q2 = Q()
# q2.connector = 'OR'
# q2.children.append(('c1', 1))
# q2.children.append(('c1', 10))
# q2.children.append(('c1', 9))
#
# con.add(q1, 'AND')
# con.add(q2, 'AND')
#
# models.Tb1.objects.filter(con) #
# from django.db import connection
# cursor = connection.cursor()
# cursor.execute("""SELECT * from tb where name = %s""", ['Lennon'])
# row = cursor.fetchone()
Django基于Q 实现ajax请求数据库
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.left{
float: left;
}
.clearfix:after{
content: '.';
clear: both;
display: block;
visibility: hidden;
height: 0;
}
</style>
</head>
<body>
<div class="condition">
<div class="item clearfix">
<div class="icon left" onclick="AddCondition(this);">+</div>
<div class="left">
<select onchange="ChangeName(this);">
<option value="name">书名</option>
<option value="book_type__caption">图书类型</option>
<option value="price">价格</option>
<option value="pages">页数</option>
</select>
</div>
<div class="left"><input type="text" name="name" /></div>
</div>
</div>
<div>
<input type="button" onclick="Search();" value="搜索" />
</div> <div class="container"> </div> <script src="/static/jquery-1.9.1.min.js"></script>
<script>
function AddCondition(ths) {
var new_tag = $(ths).parent().clone();
new_tag.find('.icon').text('-');
new_tag.find('.icon').attr('onclick', 'RemoveCondition(this);'); $(ths).parent().parent().append(new_tag);
}
function RemoveCondition(ths) {
$(ths).parent().remove();
}
function ChangeName(ths) {
var v = $(ths).val();
$(ths).parent().next().find('input').attr('name',v);
}
function Search() {
var post_data_dict = {}; // 获取所有input的内容，提交数据
$('.condition input').each(function () {
// console.log($(this)[0])
var n = $(this).attr('name');
var v = $(this).val();
var v_list = v.split('，');
post_data_dict[n] = v_list;
});
console.log(post_data_dict);
var post_data_str = JSON.stringify(post_data_dict);
$.ajax({
url: '/index/',
type: 'POST',
data: { 'post_data': post_data_str},
dataType: 'json',
success: function (arg) {
// 字符串 "<table>" +
if(arg.status){
var table = document.createElement('table');
table.setAttribute('border',1);
// [{,name,pubdate,price,caption},]
$.each(arg.data, function(k,v){
var tr = document.createElement('tr'); var td1 = document.createElement('td');
td1.innerText = v['name'];
var td2 = document.createElement('td');
td2.innerText = v['price'];
var td3 = document.createElement('td');
td3.innerText = v['book_type__caption'];
var td4 = document.createElement('td');
td4.innerText = v['pubdate'];
tr.appendChild(td1);
tr.appendChild(td2);
tr.appendChild(td3);
tr.appendChild(td4); table.appendChild(tr);
}); $('.container').empty();
$('.container').append(table);
}else{
alert(arg.message);
} } })
}
</script>
</body>
</html>
index.html
from django.shortcuts import render,HttpResponse
from app01 import models
# Create your views here.
import json
def test(request):
# models.BookType.objects.create(caption='技术')
# models.BookType.objects.create(caption='文学')
# models.BookType.objects.create(caption='动漫')
# models.BookType.objects.create(caption='男人装') # models.Book.objects.create(name='文艺复兴',pages='100',price='40',pubdate='1992-11-2',book_type_id='1')
# models.Book.objects.create(name='解密',pages='80',price='10', pubdate='2016-6-10',book_type_id='2')
# models.Book.objects.create(name='刀锋',pages='50',price='3', pubdate='2014-02-16',book_type_id='2')
# models.Book.objects.create(name='查令十字路84号',pages='260',price='40',pubdate='1999-10-12',book_type_id='3')
# models.Book.objects.create(name='红楼',pages='1000',price='500', pubdate='1760-1-1',book_type_id='3')
# models.Book.objects.create(name='将夜',pages='2000',price='300', pubdate='2010-3-3',book_type_id='1')
# models.Book.objects.create(name='mysql从删库到跑路',pages='20',price='10',pubdate='1998-9-2',book_type_id='4')
# models.Book.objects.create(name='马克思主义',pages='50',price='100',pubdate='1937-3-3',book_type_id='2') return HttpResponse('ok') import json
from datetime import date
from datetime import datetime
from decimal import Decimal
class JsonCustomEncoder(json.JSONEncoder): def default(self, field): if isinstance(field, datetime):
return field.strftime('%Y-%m-%d %H:%M:%S')
elif isinstance(field, date):
return field.strftime('%Y-%m-%d')
elif isinstance(field, Decimal):
return str(field)
else:
return json.JSONEncoder.default(self, field) def index(request):
if request.method == 'POST':
print(request.POST.get('post_data',None))
ret = {'status': False, 'message': '', 'data':None}
try:
post_data = request.POST.get('post_data',None)
post_data_dict = json.loads(post_data)
print(post_data_dict,type(post_data_dict))
# {'name': ['11', 'sdf']，'price': ['11', 'sdf']}
# 构造搜索条件
from django.db.models import Q
con = Q()
for k,v in post_data_dict.items():
q = Q()
q.connector = 'OR'
for item in v:
print(v,type(v))
q.children.append((k, item))
con.add(q, 'AND')
"""
ret = models.Book.objects.filter(con)
print(ret) # queryset,[对象] from django.core import serializers
data = serializers.serialize("json", ret)
print(type(data),data)
# 字符串
"""
"""
# ret = models.Book.objects.filter(con).values('name','book_type__caption')# 列表里面以字典的形式
# #ret = models.Book.objects.filter(con).values_list('name', 'book_type__caption')# 列表里面以元组的形式
#
# li = list(ret)
# data = json.dumps(li)
# print(data,type(data))
"""
result = models.Book.objects.filter(con).values('name','price','pubdate','book_type__caption')
# ret = models.Book.objects.filter(con).values_list('name', 'book_type__caption') li = list(result) ret['status'] = True
ret['data'] = li
except Exception as e:
ret['message'] = str(e)
ret_str = json.dumps(ret, cls=JsonCustomEncoder) return HttpResponse(ret_str)
return render(request, 'index.html')
Views.py
from django.db import models # Create your models here.
class Author(models.Model):
name = models.CharField(max_length=20)
age = models.IntegerField() class BookType(models.Model):
caption = models.CharField(max_length=64) class Book(models.Model):
name = models.CharField(max_length=64)
pages = models.IntegerField()
price = models.DecimalField(max_digits=10, decimal_places=2)
pubdate = models.DateField() book_type = models.ForeignKey(BookType)
models
# 注意这个 是django自带的序列化 但是它不支持时间 小数等格式
ret = models.Book.objects.filter(con)
print(ret) # queryset,[对象] from django.core import serializers
data = serializers.serialize("json", ret)
print(type(data),data)
# 字符串
这是通过 映射 取到值
"""
"""
# ret = models.Book.objects.filter(con).values('name','book_type__caption')# 列表里面以字典的形式
# #ret = models.Book.objects.filter(con).values_list('name', 'book_type__caption')# 列表里面以元组的形式
#
# li = list(ret)
# data = json.dumps(li)
# print(data,type(data))