Specify database to use in Django - python

I need to use multiple databases for my django project. The application works fine when there is only one database:
In setting.py
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'mydb',
'USER': 'root',
'PASSWORD': '',
'HOST': '127.0.0.1',
'PORT': 3306,
},
But if I added more databases from the same engine:
DATABASES = {
'default':{},
'mydb1': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'mydb1',
'USER': 'root',
'PASSWORD': '',
'HOST': '127.0.0.1',
'PORT': 3306,
},
'mydb2': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'mydb2',
'USER': 'root',
'PASSWORD': '',
'HOST': '127.0.0.1',
'PORT': 3306,
}
}
it gives me following error:
ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.
Also, i tried:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'mydb1',
'USER': 'root',
'PASSWORD': '',
'HOST': '127.0.0.1',
'PORT': 3306,
},
'mydb2': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'mydb2',
'USER': 'root',
'PASSWORD': '',
'HOST': '127.0.0.1',
'PORT': 3306,
}
}
It only sees mydb1, not mydb2, when i tried query mydb2, it gives me:
DoesNotExist: Site matching query does not exist.
Do I need to define database route? it seems that I only need to do that for customized read/write.
Thanks
UPDATE:
In django docs, it says "The default routing scheme ensures that if a database isn't specified, all queries fall back to the default database".
So I guess my actual question is how do I specify a database to use for my queries?

It is explicetely stated in docs
The DATABASES setting must configure a default database; any number of
additional databases may also be specified.
If the concept of a default database doesn’t make sense in the context
of your project, you need to be careful to always specify the database
that you want to use.
As in your second example default database is not configured
DATABASES = {
'default':{},
...
}
when you access your data with no database specified, a django.db.backends.dummy backend is used, which complains on your configuration with ImproperlyConfigured error.
An example of configuring multiple database usage with Database Routers can be found in docs
update
Site matching query error is for completely different reasons, and is another question. Answer here, as it is duplicate of many others: as your mysql1 and mysql2 dbs have different content, second one seems to not to be properly configured. Refer site matching query does not exist.

Related

python/django database connection issue

Database settings
DATABASES = {
'default': {
'ENGINE': os.environ.get('DB_ENGINE', "mysql"),
'NAME': os.environ.get('DB_NAME', "django_db"),
'USER': os.environ.get('DB_USER', "root"),
'PASSWORD': os.environ.get('DB_PASS', "123456798"),
'HOST': os.environ.get('DB_HOST', "localhost"),
'PORT': os.environ.get('DB_PORT'),
}
}
error
django.core.exceptions.ImproperlyConfigured: 'mysql' isn't an available database backend or couldn't be imported. Check the above exception. To use one of the built-in backends, use 'django.db.backends.XXX', where XXX is one of:
'mysql', 'oracle', 'postgresql', 'sqlite3'
Connecting with mysql to generate migration but facing issue
Its my first time and facing following above issue please guide.
Instead of :
mysql in 'ENGINE': os.environ.get('DB_ENGINE', "mysql"),
Try this:
'ENGINE': os.environ.get('DB_ENGINE', "django.db.backends.mysql"),
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'django_db',
'USER': 'root',
'PASSWORD': '123456798',
}
}
Try this to establish a connection.
I don't usually add HOST or Port but it still connect to database.
I only mention Host or Port if they don't have the default settings.

How to indicate to a specific version of database? [Django] [PostgreSQL]

I using django version 3.0.2.
I'd like to use postgreSQL as my instance db.
And there are two version postgreSQL in server.
After config setting.py DATABASES parameter, and runserver.
It showed error.
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'dj_web_console',
'USER': 'django',
'PASSWORD': 'django',
'HOST': 'localhost',
'PORT': '',
}
}
psycopg2.OperationalError: FATAL: password authentication failed for user "django"
I'm sure that the username and password are correct.
How to config pg_path in Django as odoo:
In this case, I can use the specific version of pgsql. And run smoothly.
I solve this by indicating the port of the version I installed.
In this case, I have a version 9.6 which install in 5432 and the other is 5433.
So I just solved this by filling in 5433.
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'dj_web_console',
'USER': 'django',
'PASSWORD': 'django',
'HOST': 'localhost',
'PORT': '5433',
}
}

How to make tests with Django using real data?

Here is my situation:
We have a project that started by the wrong way, without testing. The Project uses Python 3.6* and Django 2.*. Anyway, now we are trying to code the tests and for this we are reading "Obey the Testing Goat" book, for Django tests.
The problem is that we are in a closed network and our system uses LDAP to make login. LDAP user is compared with our Workers database and, if the worker was not fired or in vacances, he can log in the system. For This Worker database (HR) we just have access to make queries, not inserts or updates, create, delete, etc... In resume, we have no power to manage LDAP and HR Database, just make queries. Other thing: we have no power (privileges) to create more than one database in our SQLServer. They created for us a TestDatabase. So, I always need to put --keepdb when I run the test command.
Also, if there is more than one database in settings, Django Tests will try to create both databases. As we have in settings.py the HR Database (it's not managed) and the Application Database (as default), Django are trying to create both databases. But the HR database is just to do queries! How to do? We can't create workers records, just use them.
In resume: can I test with real data, making queries from a real database instead the temporary database created by Django? Can you help me, please? Any idea?
if 'test' in sys.argv:
DATABASES = {
'default': {
'ENGINE': 'sql_server.pyodbc',
'NAME': 'MarcoMob_TEST',
'USER': 'MarcoMob_TESTuser',
'PASSWORD': 'a_strong_password',
'HOST': 'SOME_HOST',
'PORT': '',
'OPTIONS': {
'driver': 'ODBC Driver 13 for SQL Server',
},
'TEST': {
'NAME': 'MarcoMob_TEST',
}
},
'rh': {
'ENGINE': 'django.db.backends.oracle',
'NAME': 'RH',
'HOST': 'SOME_HOST_FOR_HR',
'USER': 'some_user_for_hr',
'PASSWORD': 'some_password',
'PORT': 'port',
}
}
else:
DATABASES = {
'default': {
'ENGINE': 'sql_server.pyodbc',
'NAME': 'MPInventoryDES',
'USER': 'MPInventorydesuser',
'PASSWORD': 'a_strong_password',
'HOST': 'SOME_HOST',
'PORT': '',
'OPTIONS': {
'driver': 'ODBC Driver 13 for SQL Server',
},
},
'rh': {
'ENGINE': 'django.db.backends.oracle',
'NAME': 'RH',
'HOST': 'SOME_HOST_FOR_HR',
'USER': 'some_user_for_hr',
'PASSWORD': 'some_password',
'PORT': 'port',
}
}

able to check db connection host or name (not db name but the setting) ? django

I am not trying to check the db name to the connection, I have multiple database setup in django and also used the database route to create a failover but I am wondering if I can get the name of the connection host or the name given to the settings...
for example
DATABASES = {
'default': { # trying to get this name 'default'
'ENGINE': 'django.db.backends.mysql',
'NAME': 'db_name',
'USER': 'euser',
'PASSWORD': 'password',
'HOST': 'host', # trying to get this host name 'host'
'PORT': 3306,
},
'node2': { # trying to get this name 'node2'
'ENGINE': 'django.db.backends.mysql',
'NAME': 'db_name',
'USER': 'euser',
'PASSWORD': 'password',
'HOST': 'host2', # trying to get this host name 'host2'
'PORT': 3306,
},
}
Is it possible to get those names I commented out above?
For my failover, I am trying to send an email if another db is being used, but it would be great if I can get especially the host so it would be easier on me
P.S. off topic, is it possible to change the name default to other names? I tried changing it and I would get errors. Seems like I must have at least one database setting name called default
Thanks in advance for any help.
So, doing:
import pprint # Makes it sooo pretty :)
from django.db import connection
print(pprint.pformat(connection.settings_dict))
Will give you the current connection settings. For instance, the code above should print something like that:
{'ATOMIC_REQUESTS': False,
'AUTOCOMMIT': True,
'CONN_MAX_AGE': 600,
'ENGINE': 'django.db.backends.postgresql',
'HOST': 'localhost',
'NAME': 'stack_overflow',
'OPTIONS': {},
'PASSWORD': '***',
'PORT': '5432',
'TEST': {'CHARSET': None, 'COLLATION': None, 'MIRROR': None, 'NAME': None},
'TEST_NAME': 'stack_overflow_test',
'TIME_ZONE': None,
'USER': 'postgres'}
So you should be able to access the hostname just by doing connection.settings_dict['HOST']

How to use inspectdb for multiple mysql schemas in django?

This is the DATABASES dictionary in my Settings.py
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'account',
'USER': 'xxxx',
'PASSWORD': 'xxxx',
'HOST': 'localhost',
'PORT': '3306'
}
}
My database has multiple schemas, for example, account, login, notifications etc.
When I do a python manage.py inspectdb, I only get the classes for the tables in the "account" schema, but I want the classes for all the schemas.
I tried doing python manage.py inspectdb --database=login, but I get a django.db.utils.ConnectionDoesNotExist exception
But, if I change the settings to
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'account',
'USER': 'xxxx',
'PASSWORD': 'xxxx',
'HOST': 'localhost',
'PORT': '3306'
},
'login': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'login',
'USER': 'xxxx',
'PASSWORD': 'xxxx',
'HOST': 'localhost',
'PORT': '3306'
},
}
I get the proper classes of the table login on executing python manage.py inspectdb --database=login. But, problem is, if this is supposed to be the procedure, I have to make an option in the DATABASES option, which will become really long, as I have more than 15 schemas, and I am not sure if doing that will be a good thing or not.
So, I want to know what is the right way of doing this.
I am on Django 1.10.5.
Django needs to know how to reach each one of your databases so you won't be able to avoid declaring them in the DATABASES setting. If your only concern is that you will loose readability, you may create a helper function to get rid of repetition.
For example:
def local_db(name):
return {
'ENGINE': 'django.db.backends.mysql',
'NAME': name,
'USER': 'xxxx',
'PASSWORD': 'xxxx',
'HOST': 'localhost',
'PORT': '3306',
}
DATABASES = {
'default': local_db('account'),
'login': local_db('login'),
# Etc.
}
If you want to inspect all databases at once, you may create a custom command to do so.
For example:
from django.conf import settings
from django.core.management.commands.inspectdb import Command as BaseCommand
class Command(BaseCommand):
def handle(self, **options):
for db_name in settings.DATABASES:
options['database'] = db_name
self.stdout.write('# Generated while inspecting database %s\n' % db_name)
super().handle(**options)

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