django
mysql
- model field type
'AutoField': 'integer AUTO_INCREMENT',
'BigAutoField': 'bigint AUTO_INCREMENT',
'BinaryField': 'longblob',
'BooleanField': 'bool',
'CharField': 'varchar(%(max_length)s)',
'CommaSeparatedIntegerField': 'varchar(%(max_length)s)',
'DateField': 'date',
'DateTimeField': 'datetime',
'DecimalField': 'numeric(%(max_digits)s, %(decimal_places)s)',
'DurationField': 'bigint',
'FileField': 'varchar(%(max_length)s)',
'FilePathField': 'varchar(%(max_length)s)',
'FloatField': 'double precision',
'IntegerField': 'integer',
'BigIntegerField': 'bigint',
'IPAddressField': 'char(15)',
'GenericIPAddressField': 'char(39)',
'NullBooleanField': 'bool',
'OneToOneField': 'integer',
'PositiveIntegerField': 'integer UNSIGNED',
'PositiveSmallIntegerField': 'smallint UNSIGNED',
'SlugField': 'varchar(%(max_length)s)',
'SmallIntegerField': 'smallint',
'TextField': 'longtext',
'TimeField': 'time',
'UUIDField': 'char(32)',
DEMO:
from django.db import models # Create your models here. class userinfo(models.Model): # id = models.IntegerField(primary_key=True) id = models.AutoField(primary_key=True) # Automatically create an id column with id as primary key and self growth telephone = models.CharField(unique=True,max_length=11) password = models.CharField(max_length=64) email = models.EmailField(null=True,db_column='uemail') regist_time=models.DateTimeField(auto_now_add=True,null=True) # In order not to add an additional user type table, Admin can use the choices field user_types=( (1,'Ordinary users'), (2,'VIP user'), (3,'Administrators') ) user_type_id=models.IntegerField(choices=user_types,default=1) # memo = models.TextField()
- model data constraint
null Whether the field in the database can be empty
db_column Column name of the field in the database
email = models.EmailField(null=True,db_column='uemail')
db_tablespace
default Default values for fields in the database
primary_key Whether the fields in the database are primary keys
telephone = models.CharField(unique=True,max_length=30)
db_index Whether fields in the database can be indexed
unique Whether fields in the database can be uniquely indexed
unique_for_date Can a unique index be created for the date part of the field in the database
unique_for_month Can a unique index be created for the [month] part of the field in the database
unique_for_year Can a unique index be created for the year part of the field in the database
auto_now_add This column automatically fills in the current system time
==
Admin Fields used in the module
verbose_name Admin Field name shown in
blank Admin Allow user input to be blank in
editable Admin Whether it can be edited in
help_text Admin Prompt for this field in
choices Admin The contents of the selection box are displayed in, and unchanging data is placed in memory to avoid cross table operation
//For example: gf = models.IntegerField(choices=[(0, 'he Sui'), (1, 'big cousin'),], default=1)
error_messages Customize the error information (Dictionary type), so as to customize the error information to be displayed;
//Dictionary key: null, blank, invalid, invalid_choice, unique, and unique_for_date
//For example: {'null': "cannot be empty.", "invalid ':' format error '}
validators Customize error validation (list type) to customize the validation rules you want
from django.core.validators import RegexValidator
from django.core.validators import EmailValidator,URLValidator,DecimalValidator,\
MaxLengthValidator,MinLengthValidator,MaxValueValidator,MinValueValidator
//For example:
test = models.CharField(
max_length=32,
error_messages={
'c1': 'Priority error message 1',
'c2': 'Priority error message 2',
'c3': 'Priority error message 3',
},
validators=[
RegexValidator(regex='root_\d+', message='Wrong', code='c1'),
RegexValidator(regex='root_112233\d+', message='Wrong again', code='c2'),
EmailValidator(message='Wrong again', code='c3'), ]
)
DEMO:
class UserInfo(models.Model):
nid = models.AutoField(primary_key=True)
username = models.CharField(max_length=32)
class Meta:
# Default app name + underline + class name of the generated table in the database
db_table = "table_name"
# Joint index
index_together = [
("pub_date", "deadline"),
]
# Union unique index
unique_together = (("driver", "restaurant"),)
# Table name displayed in admin
verbose_name
# Verbose? Name plus s
verbose_name_plural
//More: https://docs.djangoproject.com/en/1.10/ref/models/options/
- Table relation
1. Relationship
-One to many: models.foreignkey (other tables)
-Many to many: models.manytomanyfield (other tables)
-One to one: models.onetoonefield (other tables)
2. Set foreign key relationship (1:n)
When the user type is saved to the database, django will automatically save the field as user type ID
user_type=models.ForeignKey("usertype",to_field="id",default=1,on_delete= models.CASCADE)
When the user type is saved to the database, django will automatically save the field as user type ID
When querying user info table data, user type ID represents index value, and user type field can also be used. Its content is a type table object, so it can get name directly
user = models.userinfo.objects.filter(telephone='root',password='999').first()
if user:
print(user.telephone)
print(user.user_type_id)
print(user.user_type.name)
Note the addition of on_delete= models.CASCADE
-models.CASCADE, delete the associated data, and delete the associated data
-Models.do'noting, delete the associated data, and raise an integrity error
-models.PROTECT, delete the associated data, raise the error ProtectedError
-models.SET_NULL, delete the associated data, and set the associated value to null (if the FK field needs to be set to nullable)
-Models.set? Default, delete the associated data, and set the associated value as the default value (if the FK field needs to set the default value)