Two options to create many-ways

Create a third table to establish themselves-many relationship

Create a table

# Teachers and students table tables may be one-many relationship, you can create a third table associated manually when construction of the table 

class Student (models.Model): 
    name = models.CharField (= max_length 32 , null = True) 
    Age models.CharField = (= MAX_LENGTH 32 , null = True) 

class Teacher (models.Model): 
    name = models.CharField (= MAX_LENGTH 32 , null = True) 
    Gender = models.CharField (= MAX_LENGTH 32 , null = True) 

# the establishment of the third table, two tables together before the association 
class TeacherToStudent (models.Model): 
    STU= models.ForeignKey('Student', null=True)
    teac = models.ForeignKey('Teacher', null=True)

CRUD operations

# Increase directly by models. .Objects.create class name added 
models.Student.objects.create (name = " xxx " , Age = 12 ) 
models.Teacher.objects.create (name = " OOO " , Gender = " M " ) 
models.TeacherToStudent.objects.create (stu_id = . 1 , teac_id = . 1 ) 

# identify objects deleted .delete (), and delete the correspondence relationship 
models.Teacher.objects.filter (ID = . 4 ) .Delete ( ) 
models.TeacherToStudent.objects.filter (teac_id = . 4 ) .Delete () 

# change as different tables operated separately 
models.Teacher.objects.filter (id= 3 ) .Update (name = " XOXO " ) 

# check, if I am asking for a student to be taught at the same time the number of teachers, there are three ways to chart at 
# 1 : 
RES = models.Student.objects.filter (the above mentioned id = 2 ) .all () # to identify eligible students
 for row in RES: 
    Print (row.name) 
    r = row.teachertostudent_set.all () # (reverse lookup) tables represent a third of all students with id 2 rows
     for i in r: 
        # i.teac # (n check) indicates that the corresponding table teacher of a 
        print (i.teac.name) # for all teachers identify student id 2 corresponds to 

# 2 : 
RES = models.TeacherToStudent.objects .filter (stu__name = " CaO" ) .All () 
# check out the names of the students for all rows (magical double underline) cao corresponding 
for Row in RES: 
    Print (row.stu.name, row.teac.name) # find students and teachers correspondence between 

# . 3 : 
RES = models.TeacherToStudent.objects.filter (stu__name = " Li " ) .values ( " teac__name " ) 
# QuerySet check out list, which contains a dictionary 
print (res)

Django method to create many relationship

Create a table

# Create tables, create a class and course-many relationship 
#-many relationship is created by django in ManyToManyField, two columns on the field can be any of a 
class the Classes (models.Model): 
    name = Models. as CharField (= MAX_LENGTH 32 , null = True) 
    Course = models.ManyToManyField ( ' Course, ' ) 
    
class Course, (models.Model): 
    name = models.CharField (= MAX_LENGTH 32 , null = True)

CRUD operations

# Increase must first find the corresponding class or course objects 
obj = models.Classes.objects.filter (id = 4 ) .first () 
added via course.add when construction of the table after # is found, take courses on the list id was beaten pass in 
obj.course.add ( 1 ) # add a 
obj.course.add ( * [ 2 , 3 ]) # increase the number 

# delete found objects. attribute name .clear when construction of the table () delete all 
obj = models.Classes.objects.filter (= ID . 4 ) .first () 
obj.course.clear () 

# reset (changed), the object is found by. SET () method, which put a list 
obj = Models .Classes.objects.filter (= ID . 3 ) .first () 
obj.course. SET ([ . 1 , 2 , . 3]) 

# Check for tables that have ManyToManyField model class field 
RES = models.Classes.objects.all () # to detect all objects
 for Row in RES: 
    Print (row.name) 
    for I in row.course .all (): # row.course.all () is that all program objects each corresponding class 
        Print (i.name) 
# ManyToManyField is no table model class field for 
RES = models.Course.objects.all ( ) # is the first to detect all objects
 for Row in RES: 
    Print ( " =================== " ) 
    Print (row.name) 
    for i in row.classes_set .all (): # corresponding to each discipline all class 
        print (i.name)

Note: Both methods establish many relationships are possible, taking into account the points which, if the relationship between the tables with a simple,

　　Third table does not require adding fields except the two tables can be created with id django But if table relationships are more complex,

　　And, third table also need to add some other fields, we need to use our custom-many relationship (

　　Manually create a third table), the structure can be customized third table