How to create ArrayField() in TortoiseORM
from common.base_model import AbstractBaseModel
from tortoise.fields import CharField, BooleanField, ForeignKeyField, ArrayField
class City(AbstractBaseModel):
name = CharField(max_length=100, unique=True)
district = CharField(max_length=100, null=True)
state = CharField(max_length=100)
country = ArrayField() # not working
is_verified = BooleanField(default=True)
There is no ArrayField in TortoiseORM, here is an article about fields in TortoiseORM from its documentation.
As you can see, there is no matching field in TortoiseORM, so you have to extend the existing field class.
I suggest extending the basic class Field because your subclass' to_db_value method has to return the same type as extended field class' to_db_value method, and in the class Field it's not specified.
Next time, try harder - read the documentation and make better questions (add more info, show your attempts).
To achieve the result you want,which I'm assuming is having a field to hold multiple countries, you'd have to create another table for your country field and have a many to many relationship between that table and your city table,its a more conventional implementation that wont have you extend the existing field class.
Related
I have a model
class StudentBasicInfo(models.Model):
usn = models.CharField(blank=False,max_length=10,unique=True,validators=[])
my usn will be in format [0-9][A-Za-z][A-Za-z][0-9][0-9][A-Z][A-Z][0-9][0-9][0-9]
I don't know how to write validation code
create a validator. I'd suggest a RegexValidator like so:
from django.core.validators import RegexValidator
...
class StudentBasicInfo(models.Model):
usn = models.CharField(blank=False,max_length=10,unique=True, validators=[RegexValidator(regex='[0-9][A-Za-z]{2}[0-9]{2}[A-Z]{2}[0-9]{3}', message='Error message goes here')])
I took the liberty of shortening your regex by combining groups that were together. If you want to make the error appear next to the field in the admin you'll have to overload a ModelForm.
I am trying to achieve a category model where name has unique=True,
but practically I can still add same category name with different cases.
i.e. I have a category called Food
I am still able to add food, FOOD, fOod, FOOd
Is their any philosophy behind this? or it is a work in progress.
Cause in real world if I think of Category Food, it will always be food, no matter what case it has used to mention itself.
Thank you in advance to look at this.
To answer my own question:
I have found I can have clean method on my model. So I added
class Category(models.Model):
name = models.CharField(max_length=200, unique=True)
def clean(self):
self.name = self.name.capitalize()
It is capitalising the first letter, which is then handled by the save method, which calls the validate_unique method to raise error.
You can use Postgre specific model field called Citext fields (case insensitive fields).
There are three option at the moment:
class CICharField(**options), class CIEmailField(**options) and class CITextField(**options)
Example:
from django.db import models
from django.contrib.postgres.fields import CICharField
class Category(models.Model):
name = CICharField(verbose_name="Name", max_length=255)
But don't forget to create an extension for the citext fields.
See here.
Basically, you have to add the extension class in the migration file, inside the operations array, before the first CreateModel operation.
# migration file
operations = [
CITextExtension(), # <------ here
migrations.CreateModel(
...
),
...,
]
Setting the column to case-insensitive collation should fix this. You may need to do it at the SQL level.
In my CakePHP application, I have a model like this:
class Duck extends AppModel {
var $name = 'Duck';
function get_table_name() {
$tbl_name = //compute default table name for this model
}
}
I would like to write the function get_table_name() that outputs the default table name for the model. For the example above, it should output ducks.
EDIT:
Several people have pointed out the use of $this->table.
I did small testing and found out the following:
In the question as I have put above, $this->table indeed contains the table name.
However, actually, my code looked more like this:
class Duck extends Bird {
var $name = 'Duck';
function get_table_name(){
$tbl_name = //comput default table name for this model
}
}
class Bird extends AppModel {
}
In this case $this->table is empty string.
I went with this approach because I wanted to share some code between two of my models. Looks like this is not a good way to share code between models which need some common functionality.
You're looking for the Inflector class.
Inflector::tableize($this->name)
(tableize calls two Inflector methods to generate the table name: underscore() and pluralize())
Edit:
According to the source code, $this->table should contain the name of the table that CakePHP will use for the model, but in my experience this isn't always set. I'm not sure why.
To get the name of the table that the model is currently using, you can use: $this->table. If you don't manually change the model's table conventions, this may be the most useful in the case of CakePHP ever changing its conventions to use table names using something other than Inflector.
CakePHP's Inflector
function get_table_name() {
$tbl_name = Inflector::pluralize($this->name);
}
OR the tableize method
function get_table_name() {
$tbl_name = Inflector::tableize($this->name);
}
Edit
This also addresses the apparent "ghost" issue with $this->table in the Model.
Digging around in the __construct for Model I discovered two things:
Cake uses Inflector::tableize() to get the table name. This alone is enough to warrant using tableize over pluralize. You'll get consistent results.
$this->table is not set by the Model::__construct() unless $this->useTable === false AND $this->table === false.
It appears that if you know you haven't set $this->useTable to false you should be able to use this over $this->table. Admittedly though I only briefly scanned the source and I haven't really dug deep enough to say why $this->table isn't working sometimes.
To get the full table name for a model you have to take the table prefix into account.
$table = empty($this->table) ? Inflector::tableize($this->name) : $this->table;
$fullTableName = $this->tablePrefix . $table;
I used to use inflector to get the table name from model's name
$tableName = Inflector::pluralize(Inflector::underscore($model));
but this is not really universal, using useTable looks better, by default it will contain table's name by convention, and if you have a table that does not match the conventions, then you should manually specify it by useTable. So, in both cases the result will be correct
$this->User->useTable
I want to implement some kind of tagging functionality to my app. I want to do something like...
class Item(db.Model):
name = db.StringProperty()
tags = db.ListProperty(str)
Suppose I get a search that have 2 or more tags. Eg. "restaurant" and "mexican".
Now, I want to get Items that have ALL, in this case 2, given tags.
How do I do that? Or is there a better way to implement what I want?
I believe you want tags to be stored as 'db.ListProperty(db.Category)' and then query them with something like:
return db.Query(Item)\
.filter('tags = ', expected_tag1)\
.filter('tags = ', expected_tag2)\
.order('name')\
.fetch(256)
(Unfortunately I can't find any good documentation for the db.Category type. So I cannot definitively say this is the right way to go.) Also note, that in order to create a db.Category you need to use:
new_item.tags.append(db.Category(unicode(new_tag_text)))
use db.ListProperty(db.Key) instead,which stores a list of entity's keys.
models:
class Profile(db.Model):
data_list=db.ListProperty(db.Key)
class Data(db.Model):
name=db.StringProperty()
views:
prof=Profile()
data=Data.gql("")#The Data entities you want to fetch
for data in data:
prof.data_list.append(data)
/// Here data_list stores the keys of Data entity
Data.get(prof.data_list) will get all the Data entities whose key are in the data_list attribute
I have the following model structure
class User(db.Model) :
nickname = db.StringProperty(required=True)
fullname = db.StringProperty(required=True)
class Article(db.Model) :
title = db.StringProperty(required=True)
body = db.StringProperty(required=True)
author = db.ReferenceProperty(User, required=True)
class Favorite(db.Model) :
who = db.ReferenceProperty(User, required=True)
what = db.ReferenceProperty(Article, required=True)
I'd like to display 10 last articles according to this pattern: article.title, article.body, article.author(nickname), info if this article has been already favorited by the signed in user.
I have added a function which I use to get the authors of these articles using only one query (it is described here)
But I don't know what to do with the favorites (I'd like to know which of the displayed articles have been favorited by me using less than 10 queries (I want to display 10 articles)). Is it possible?
You can actually do this with an amortized cost of 0 queries if you denormalize your data more! Add a favorites property to Authors which stores a list of keys of articles which the user has favorited. Then you can determine if the article is the user's favorite by simply checking this list.
If you retrieve this list of favorites when the user first logs in and just store it in your user's session data (and update it when the user adds/removes a favorite), then you won't have to query the datastore to check to see if an item is a favorite.
Suggested update to the Authors model:
class Authors(db.Model): # I think this would be better named "User"
# same properties you already had ...
favorites = db.ListProperty(db.Key, required=True, default=[])
When the user logs in, just cache their list of favorites in your session data:
session['favs'] = user.favorites
Then when you show the latest articles, you can check if they are a favorite just by seeing if each article's key is in the favorites list you cached already (or you could dynamically query the favorites list but there is really no need to).
favs = session['favs']
articles = get_ten_latest_articles()
for article in articles:
if article.key() in favs:
# ...
I think there is one more solution.
Let's add 'auto increment' fields to the User and Article class.
Then, when we want to add an entry to the Favorite class, we will also add the key name in the format which we will be able to know having auto increment value of the signed in user and the article, like this 'UserId'+id_of_the_user+'ArticleId'+id_of_an_article.
Then, when it comes to display, we will easily predict key names of the favorites and would be able to use Favorite.get_by_key_name(key_names).
An alternative solution to dound's is to store the publication date of the favorited article on the Favorite entry. Then, simply sort by that when querying.