1, the first django orm automatically help us in the creation of the table to create table relationships
from django.db import models
# Create your models here.
# Create a book table
class Book(models.Model):
name=models.CharField(max_length=32)
# The first way, the system automatically creates a table to help us book author and relationship table
authors=models.ManyToManyField(to='Author')
Create a table of #
class Author(models.Model):
name=models.CharField(max_length=32)
Book_authors table is automatically created out of the author and book tables for association
2. Create a table (third table) the second pure manual
from django.db import models
# Create your models here.
# Create a book table
class Book(models.Model):
name=models.CharField(max_length=32)
# # The first way, the system automatically creates a table to help us book author and relationship table
# authors=models.ManyToManyField(to='Author')
Create a table of #
class Author(models.Model):
name=models.CharField(max_length=32)
class Book2Author(models.Model):
book=models.ForeignKey(to='Book')
author=models.ForeignKey(to='Author')
info=models.CharField(max_length=32)
Benefits manually create relational tables is that you can create custom fields in relational tables; drawback is that you can not use orm
3, the third semi-automatic create a third table (scalable high surname, in line with orm inquiry)
from django.db import models
# Create your models here.
# Create a book table
class Book(models.Model):
name=models.CharField(max_length=32)
# # The first way, the system automatically creates a table to help us book author and relationship table
# authors=models.ManyToManyField(to='Author')
authors=models.ManyToManyField(to='Author',through='Book2Author',through_fields=('book','author'))
Create a table of #
class Author(models.Model):
name=models.CharField(max_length=32)
# books=models.ManyToManyField(to='Book',through='Book2Author',through_fields=('author','book'))
class Book2Author(models.Model): book=models.ForeignKey(to='Book') author=models.ForeignKey(to='Author') info=models.CharField(max_length=32)
Semiautomatic need to create relational tables, you can customize fields, you can query in line orm
By orm query data:
from django.test import TestCase
# Create your tests here.
import os
import sys
if __name__ == "__main__":
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "test01.settings")
import django
django.setup()
from app01 import models
# Query corresponding author books
models.Book.objects.filter = RES (= PK. 1) .values ( 'authors__name') # underlined based
print (res)
book_obj=models.Book.objects.filter(pk=1).first()
res=book_obj.authors.all()
print(res)
Front and rear ends data transmission encoding format contentType
urlencoded
A data format: name = jason & password = 555
Back-end data acquisition: request.POST
Note: django urlencoded coded data analyzer will automatically placed request.POST
formdat to:
Encoding format file transfer sheet form
Back-end data acquisition file formats: request.FILES
Back-end data acquisition ordinary key-value pairs: request.POST
application/json
ajax json format data transmission
Note that: encoding data format to keep up
ajax
1, the front end of ways in which requests can be sent toward the rear end
Browser window to manually enter the URL get request
href attribute request to get a tag
form form get / post request (get request default)
ajax get / post request
2, ajax features:
Asynchronous submitted
Partial refresh
3, ajax basic grammar
Address submitted (url)
Submission of the (type)
Submitted data (data)
Callback function (Success)
$ ( '# d1') the Click (function () {.
$ .Ajax ({
// address submitted
url: '/ index /',
the way // submission
of the type: 'POST',
// submitted data
data: { 'name': 'Jason', 'password': '123'},
// callback
success: function (data) {// data is submitted asynchronously received results returned
Alert (data)
}
})
})
4, ajax default transmission data encoding format is urlencoded
5, the front end of the back-end data transmission, data is what format they should tell others what format (encoded data to one correspondence)
Data transfer format ajax json
$ ( '# d1') the Click (function () {.
$ .ajax ({
url: '', // url parameter can not write, the default is to open the current page address
of the type: 'POST',
contentType: 'the Application / JSON ',
Data: the JSON.stringify ({' name ':' Jason ',' Hobby ':' Study '}),
Success: function (Data) {
{#alert (Data)} #
{# $ (' # I3 ') .val (Data) #}
}
})
});
Ajax transfer file
$ ('. # D1 ') the Click (function () {
the let FormData the FormData new new = ();
// can not pass the FormData target document also Common key can be transferred to
formdata.append ( 'name', 'Jason');
// Get input block storage file
// $ ( '# i1') [0].files[0]
formdata.append('myfile',$('#i1')[0].files[0]);
.ajax $ ({
url: '',
of the type: 'POST',
the Data: FormData,
// ajax to send the file you need to modify two fixed parameters
processData: false, // tell the browser not handle my data
contentType: false, // Do not use any encoding, to use my own formdata encoding format, Django can automatically identify objects change formdata
// callback
Success: function (Data) {
Alert (Data)
}
})
});
form forms with ajax similarities and differences
1.form form does not support asynchronous submit partial refresh
2.form form transport json format data do not support
3.form form with ajax default encoding format for transmitting data is urlencoded
Bulk insert data
L = []
for I in Range (10000):
l.append (models.Book2 (name = '% s of the book'% I))
models.Book2.objects.bulk_create (L) Bulk insert data #
added: <li> <a href="?page=1"> 1 </a> </ li> # automatically complete the current path
custom pager
page rendering are typically singular 1,3,5,7, 9, symbol Chinese people's aesthetic standards
need to be perfected
1. plus first and last page
2. page number should be fixed
using a custom finisher
backend:
book_list = models.Book2.objects.all ()
# data total number of
ALL_COUNT are book_list.count = ()
# this page
current_page = request.GET.get ( 'page',. 1)
# example a tab object
page_obj = my_page.Pagination (current_page = current_page, ALL_COUNT are = ALL_COUNT are)
# of total slice the data
page_queryset = book_list [page_obj.start: page_obj.end]
front end:
{{page_obj.page_html |}} # Safe render help you with that pager style bootstrap