Questions tagged [django]
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42
questions
1
vote
1answer
45 views
Duplicate key errors in Postgres queue-like table when rows should be locked by SELECT FOR UPDATE SKIP LOCKED
I have a table called queue with items that need to be processed:
CREATE TABLE public.queue (
id serial NOT NULL
CONSTRAINT queue_pkey
PRIMARY KEY
);
Another table process ...
0
votes
1answer
91 views
Vehicle database design - Type, Make, Model, Vehicle
I kindly ask you for advice, if I am correct with my DB design. I am writing an app in Django (it has its own ORM), which will use PostgreSQL.
My expectation is, that I will specify:
Type (example: ...
0
votes
0answers
64 views
How to backup a postgresql db to export on AWS lightsail
I want to take a backup from my postgresql db which I use for my Django project.
I'm using ubuntu 18.04 and want to import it in AWS lightsail.
I read pgadmin docs on how to take a backup with a ...
0
votes
0answers
25 views
Descriptive Financial Statement - SQL [duplicate]
Consider a financial system, where the customer demands a financial statement consisting of
| opening_balance | amount_credited | amount_debited | closing_balance | remarks.
Two approaches to doing ...
0
votes
0answers
14 views
How do I generate the default collections from a fresh Django installation inside a Mlab database?
When I use Djongo to install the default Django installation migrations onto my local computer server's MongoDB Compass sever, the collections such as 'auth_group', 'auth_group_permissions', '...
0
votes
1answer
401 views
How to upgrade Mysql 5.5 to 5.6 without data loss on aws-ec2?
MySQL server (5.5) is running on aws-ec2 instance with following linux details
NAME="Amazon Linux AMI"
VERSION="2015.09"
ID="amzn"
ID_LIKE="rhel fedora"
...
0
votes
0answers
14 views
How to design database with post sharing with public, specific users or hide from specific users
I am new to database design, so please ignore if i am asking very simple, but i have searched a lot about this but didn't found some helping material.
So, the question is, I want to design a database ...
1
vote
2answers
93 views
Explaining recurring crash in postgresql deployment
I'm having trouble with unexpected system crashes emanating from a postgresql deployment on a moderately busy production server (Django 1.8 app deployed on DO droplet with a gunicorn application ...
0
votes
0answers
61 views
MemoryError with django app
I develop a django application with Postgres.
On my local host where I develop the app, I use ./manage.py run to launch my app and it works successfully even with queries that produces huge output.
...
1
vote
1answer
517 views
Designing a multi-tenant database for a scenario with multiple user types
I'm developing a SaaS application for recruiting which has multiple user types such as Client, Recruiter, Panellist and Owner etc. There is also a chance that the user types may increase.
The Owner ...
0
votes
1answer
51 views
Why aren't read-only queries executing concurrently? [closed]
I have a Django app using either sqlite or Postgres. (I've tried both and encountered the same problem.) Requesting a particular endpoint results in a read-only query like this that takes 1.5-3 ...
1
vote
0answers
112 views
django-admin: postgresql trigger function
I have this table in django admin site the (Student_enrollment_record),
if i select an student and update/save the Section field
and it will search the Section field on what i select on the table (...
-1
votes
1answer
2k views
How to downgrade sqlite3 that comes with Python and Django
So I am stuck in this problem: https://stackoverflow.com/questions/53637182/django-no-such-table-main-auth-user-old
I can't upgrade Django because many other applications are connected to it using ...
2
votes
1answer
103 views
UUID as primary key and download ID
I'm designing a Django Rest Framework API with PostgreSQL. In the database I'll be recording information about documents which can be requested for download. I want the request to include a unique id, ...
-3
votes
1answer
38 views
How to copy data from a table to another in O(1) time complexity?
I have a table Customer with fields id, account_balance, etc. At the end of every month at midnight I want to copy the whole list of customers with their account balance to another table(month, year, ...
0
votes
0answers
11 views
Django - Database design improvement
In a simple scenario, where I have many measurements table that describe the measurements that comes from a specific protocol and every measurement is linked to the respective parent device, I was ...
1
vote
0answers
46 views
How to model complex relationship between three Models in Django
I have to model the following entities: BuildingSite, Company, Worker.
Each entity has a many-to-many relationship with the other entities, and each relationship some attributes like start_date, ...
0
votes
0answers
363 views
Building an Entity-Relationship Diagram for a Language Dictionary
I need advice on how to build entity-relationship diagram (ERD) for Language Dictionary. Since I did not build ERD before, I will try to explain and show the ultimate goal of this project below.
...
0
votes
0answers
820 views
Authintcation error 28000 + 18456
I have been trying to link my mssql database to Django. When I run the Django server I get the error below. For normal query (out of Django), it works fine, however, the Django doesnt even connect. ...
0
votes
1answer
455 views
django_session table killing my MySQL server and django app
I need your help
I hav a Django app that is about 7 years old and have been degrading now..every time the website goes down and back up and the issue is with mysql server
Usually i need to just ...
3
votes
0answers
466 views
Database Design for tracking user flow
I want to design a user tracking system between different tables/models. I want to track the user's progress. There is a Module table which is related to sections and sections are related to sub-...
1
vote
0answers
137 views
Why my heap read/heap hit ratio is negative?
I have a database with 200k rows (one of this column is a jsonb data type column), i'm using this database to store some various devices informations (currents, pressure, etc...) and i'm using this ...
1
vote
0answers
353 views
PGPool II + Django w/ psycopg2 load balancing
I've a pool of applications running django 1.6 with psycopg2 on top of a PGPool II with two backends PostgreSQL servers. But all queries (read and/or write) are going to master PostgreSQL even SELECT.
...
1
vote
0answers
67 views
Scalable way to manage aggregated statistics over time in hierarchy?
I'm using a closure table (Postgres through Django) to roll up stats through a hierarchical tree. When a node that is 10 layers deep has a value that increases, each parent's sum total of that value ...
4
votes
1answer
5k views
Django postgres multiple schema
I'm trying to develop a django interface for an existing postgresql db, the db makes use of various schemas, looking at the literature the following example should work, but it only returns the schema ...
1
vote
2answers
11k views
How to fix all duplicate key value violates unique constraint
I have a Postgres database that I created with a Django application. When I transferred it over, it never reindexed anything and it gives me errors trying to do this. It seems as if there are lots of ...
0
votes
1answer
73 views
Mongo DB Memory Utilisation freezes app needs restart
I am running a project using Mongo DB and Django, I have 2 separate instance for my Django project and database each 16GB ram t2xlarge ubuntu ec2 instances.
I am facing issue that within a day or two ...
3
votes
1answer
108 views
Modelling a database for a travelling business that involves Vehicules, Routes, Subroutes and Prices
I am working on travelling app, where users can book online vehicles to travel.
On the customer side I would like this flow:
Users have to select a from location and a to location
Enter how many ...
0
votes
1answer
931 views
MySQL select returns no rows while there are many
I'm using django to create a database and I manually created a test values in the database by creating objects and saving them to the database.
Now when I run this query:
select TABLE_NAME,
...
1
vote
2answers
3k views
Psycopg2 - PGBouncer - Postgresql > Server does not support SSL but SSL was required
I've setup my Django application to use SSL while connecting to the Postgresql database via pgbouncer. I'm using Psycopg2 library.
I've done this before successfully, so I just did the same steps ...
2
votes
2answers
215 views
Getting Postgres CREATE TABLE statements
I created some tables (9, to be exact) with a Django (1.9.6) migration and now I'm trying to get simple CREATE TABLE statements for them. I tried this answer, but using pg_dump in this way gives me ...
0
votes
1answer
54 views
Concurrent usage of rdbms, write 4K rows without lockdown [closed]
I am working on a django project using Postgresql. The use case is as follows:
A user needs to upload an excel (containing 2.5-4K rows) 2-3 times daily. There will be 100s of users (somewhere between ...
0
votes
1answer
931 views
MySQL query taking a long time
I have a performance issue with a MySQL query that takes a long time. I'm trying to figure out why.
I'm using Django, a web framework that comes with ORM (Object relational Mappers) and basically ...
2
votes
1answer
108 views
Field/datatype for searchable address components?
I'm using Django with Postgres, and I'm looking for a field/datatype to store address components that come from Google Places API in this format:
"address_components": [
{"long_name": "27", "...
1
vote
1answer
75 views
Are lots of columns or joins better in Django
I am writing a simple Django app that stores and displays user objects with lots of attributes.
The user may have up to three hundred attributes.
These attributes however, can be grouped off.
For ...
0
votes
1answer
2k views
AWS Postgres RDS dumping data into sql format
My team has hosted a django project in AWS with a Postgres RDS instance. What is the proper way to get export the database into SQL or pg_dump?
0
votes
1answer
459 views
Django Multi Table Inheritance and Preserving Child and Child History
Place can have many different one to one fields, that’s why it can have bookstore, restaurant, and hardware store. But can the same place be both a bookstore and a restaurant at the same time? Now if ...
0
votes
1answer
33 views
Make a boolean false after every n number of minutes in MySQL
I have a table with a boolean value, if that value is not explicitly set to anything in the database for a few minutes by the back-end (django) then it must automatically be set to false. How do I do ...
2
votes
1answer
134 views
Postgresql tables seem duplicated (with suffixes such us pkey, hashes, etc)
due to some problems I came to check the state of my current database in production and I found that some tables are "duplicated". By duplicated I mean that there appear to be some clones of the ...
1
vote
0answers
31 views
Great slowdown of Django object list retrieval after moving from sqlite3 to mySQL on Amazon RDS
Be warned, there will be some Python programming stuff; my problem is tightly connected to database engine differences though - or at least I think so.
tl;dr: Querying for list of items and all ...
2
votes
1answer
2k views
Database in postgresql with missing rows, how to fill the missing rows with a backup copy?
I have a big problem and I'm not that good with postgresql since I use Django to make queries and I only have the basics of sql for querys.
My problem is that there was a problem where a super user ...
0
votes
1answer
506 views
Django Auth user as well as custom users table?
So we've been using djangos database authentication for a while now and have recently decided we want to implement a completely new login system for our website.
We are keeping the django ORM as we ...
