Basically I want to join a bunch of tables together and display it, My tables are sort of as follows:
class A(models.Model):
name = models.CharField(max_length=60)
class B(models.Model):
a = models.ForeignField(A)
class C(models.Model):
a = models.ForeignField(A)
class D(models.Model):
a = models.ForeignField(A)
This is the basic structure of my system, I want to join all the tables with the foreign field to the table A.
I want to also be able to display in xml using Tastypie, aka ?format=xml, I have been able to display one table on its own but it seems like it is impossible to do the type of join I want even though it would be a very simple SQL query.
I have found an answer to this problem elsewhere: http://djangoandlove.blogspot.com/2012/11/tastypie-following-reverse-relationship.html
Related
I'm new to MS Access and am trying to speed up a data gathering process that is taking forever in Powershell. In Powershell I have 10 or so web API calls to get data and each comes back as an object with multiple properties (fields.) Each set of data has related fields to 1 or more of the other sets of data. Getting the data is very quick but piping an array of objects to where-object to select-object takes over an hour and there's really not that much data. Each object contains 500-1500 "records" and 5 to 10 "fields" so I thought why not export that data and use something that's intended to search through data to do the job? I exported each object as a separate .CSV file. So enter MS Access..
I imported each of the CSV's as a separate table (easy enough.) I'm going to simplify this down for this example to the following 3 tables:
[Tables]https://i.stack.imgur.com/UCH1F.jpg
Every table has fields that relate it over to other tables. Pretty much there's some sort of Id field in every table that is related to another Id field in a different table that I need to pull a field called "name" from. I'm trying to follow the bread crumbs from the Player name to it's Network name to it's Application name, to it's Layout name, etc... I want to build a query that I would eventually just be able to export as an Excel file. I also would prefer to just write out the SQL unless it's really easier to to understand the visual query builder. I'm looking to build a sheet with the following information:
Player's Name would include all names from the Players table and getting just that data makes sense to me. SELECT Name AS PlayerName FROM Players Everything else, not so much. I feel like this will end up being some mega query as I get deeper into related table after related table. In Excel, it would be straightforward using Vlookups across tabs but that doesn't seem to be the best approach. Given the info above, I'm trying to achieve the following output:
Result table
Any help with strategy and syntax greatly appreciated!
You're looking for the JOIN clause.
SELECT
Players.Name PlayerName, Networks.Name PlayerNetwork, Applications.Name ApplicationName
FROM
Players
LEFT OUTER JOIN
Networks
ON
Networks.ID = Players.NetworkId
LEFT OUTER JOIN
Applications
ON
Applications.Id = Players.ApplicationID
I'm a Django beginner. I have two models that I would like to display as one table in the Django admin interface. Below are the simplified versions of the models:
class Final_Application_Personal_Detail(models.Model):
user = models.ForeignKey(User)
name = models.CharField(max_length=20)
id_no = models.CharField(max_length=14)
class Final_Application_Beneficiary_Detail(models.Model):
user = models.ForeignKey(User)
beneficiary_name = models.CharField(max_length=20)
beneficiary_id_no = models.CharField(max_length=14)
I suppose because these two models conceptually form part of one form (a Final_Application form), I could have maybe used Django's formwizard - however, because in reality both personal details and beneficiary details are quite a lot to fill in, I thought I'd want to give the user a chance to fill them in separately (in django formwizard, as far as I know, if the user doesn't fill out all the data at once, then all previous data is also lost because the form can't be saved with unvalidated fields).
I want to join the two models in Django admin so that the administrative user can see all a user's information (personal details and beneficiary's details) on one page. So, I'd like to do an inner join on the above-mentioned tables on the field 'user'. The SQL would look like this:
SELECT *
FROM Final_Application_Personal_Detail
JOIN Final_Application_Beneficiary_Detail
ON Final_Application_Personal_Detail.user = Final_Application_Beneficiary_Detail.user
With regards to Django's ORM, I've looked into the keyword argument related_to in order to join the tables. I don't think that will work, however...it seems as if 'select_related' is just another way to stipulate a foreign key. I now want to use raw SQL in order to join the tables. I've tried using the cursor function to implement raw SQL, but I don't quite know how to implement it so that the output shows in Django's admin interface. Also, I'm a little bit afraid of using raw SQL, because as far as I understand, raw SQL can introduce security risks (I've read that Django's ORM prevents SQL injections).
Thank you for your help.
You can't do this with django admin. However, you can use inlines to edit both models in the User admin.
from django.contrib import admin
from django.contrib.auth.models import User
from django.contrib.auth.admin import UserAdmin
class Final_Application_Personal_DetailInline(admin.StackedInline):
model = Final_Final_Applicationl_Detail
class Final_Application_Beneficiary_DetailInline(admin.StackedInline):
model = Final_Final_Application_Beneficiary_Detail
admin.site.unregister(User)
#admin.register(User)
class CustomUserAdmin(UserAdmin):
inlines = [
Final_Application_Personal_DetailInline,
Final_Application_Beneficiary_DetailInline,
]
So, basically, I have two tables called "dadoscatalogo" and "palavras_chave", with a common field, "patrimonio" which is the primary key of "dadoscatalogo".
I'm using a servlet to connect to the database with these tables, and passing a query to search for entries based on some search criteria that's defined by the user.
Now, since the user can search for entries based on information present in both tables, I need to do an INNER JOIN, and then use WHERE to search for that info. I'm also using LIKE, because the user may pass just part of the information, and not all of it.
So, to test it all out, I tried passing it a few parameters to work with, and see how it went. After some debugging, I found out that there was some mistake in the query. But I can't seem to be able to point out exactly what it is.
Here's the test query:
SELECT dadoscatalogo.patrimonio
FROM dadoscatalogo
INNER JOIN palavras_chave
ON dadoscatalogo.patrimonio=palavras_chave.patrimonio
WHERE dadoscatalogo.patrimonio LIKE '%'
AND dadoscatalogo.titulo LIKE '%tons%'
OR palavras_chave.palchave LIKE '%programming%';
So, basically, what I'm trying to do with this query is, get all the primary keys from "dadoscatalogo" that are linked to a record with a "titulo" containing "tons", or a "palchave" containing "programming".
PS. Sorry for the names not being in English, hopefully it won't be too much of a distraction.
EDIT: Right now, the tables don't have much:
This is the dadoscatalogo table:
http://gyazo.com/fdc848da7496cea4ea2bcb6fbe81cb25
And this is the palavras_chave table:
http://gyazo.com/6bb82f844caebe819f380e515b1f504e
When they join, I'm expecting it to have 4 records, and it would get the one with patrimonio=2 in dadoscatalogo (which has "tons" in titulo), and the one with palchave=programming (which would have patrimonio=1)
As per my understanding run below query:
SELECT dadoscatalogo.patrimonio
FROM dadoscatalogo
INNER JOIN palavras_chave
ON dadoscatalogo.patrimonio=palavras_chave.patrimonio
WHERE dadoscatalogo.titulo LIKE '%tons%'
OR palavras_chave.palchave LIKE '%programming%';
.Hi i'm working with Asp and SQL-Server and i have no problem with writing dynamic query
I'm trying to Write a search page for searching people.
I have 3 related tables:
See my table diagram in : http://tinypic.com/r/21159go/5
What i'm trying to do is to design a search page that a person can search users with a dynamic number of attributes.
Example:
think that a username called "User1" has 3 attributes named "Attr1", "Attr2" and "Attr3" related to him in "UserAttributes" table and "User2" has 3 attributes named "Attr1", "Attr2" and "Attr4".
Attribute names and other bunch of items unrelated to search function saved in "Attributes" Table. This is because i want to relate an attribute between multiple users. and their values are stored in "UserAttributes" table.
Well someone wants to search upon "Attr1" and "Attr2" and wants to return all users that have "Attr1" and "Attr2" with specific value.
I need a query to know how to implement this. I can write a dynamic query with asp.net so if someone please give me a query for this one example i have brought, i would be thankful
P.S. This is not my real database. my real database is much more complex and has more fields and tables but i just cut it and brought only necessary items. and because attributes are very dynamic they can't be embedded in table columns.
Thanks in advance
Based on your DB diagram your code would be something like this
update:
SELECT u.*
FROM users AS u
LEFT OUTER JOIN UserAttributes AS ua1
ON u.USER_ID = ua1.USER_ID
LEFT OUTER JOIN UserAttributes AS ua2
ON u.USER_ID = ua2.USER_ID
WHERE (
ua1.attribute_id = 'att1'
AND ua.attribute_value = 'MyValue' )
AND (
ua2.attribute_id = 'att2'
AND ua.attribute_value = 'MyValue2' )
In where clause you would specify the attirbute_Id and what value you are expecting out of it. Than just decide if you want to restrict users to have all values match or just one of them, in that case modify AND between statements to be OR
if you just want to do this quick and dirty you can create your own class library that can create adhoc sql that will pass to the database.
if you want more organized matter, create SP that will bring back users and accepts any left of id and value. Do a lot of that by passing list separated by comma, colon or semicolon. Than split it up in SP and filter results based on those values
there are many other alternatives like EntityFramework, LINQ-to-SQL and other options, just need to figure out what works best for you, how much time you want to spend on it and how easy will it be to support later.
So, another in my series of Kohana 3 ORM questions :)
I have, essentially, a pivot table, called connections. The connections table connects a song to a keyword. That's all great and working (thanks to my last two questions!)
I want to output the most connected songs by keyword. So, to somehow query my connections table and output an object (with an arbitrarily limited number of iterations $n) that ranks songs by the number of times they have been connected, ie. the number of times that particular song_id appears for that particular keyword_id.
I have literally no idea how to achieve this, without querying every single row (!!!) and then counting those individual results in an array.... There must be a more elegant way to achieve this?
I believe this is more of an SQL question. Using the DB query builder:
DB::select('songs.*')->select(array('COUNT("keywords.id")', 'nconnections'))
->from('songs')
->join('connections', 'LEFT')->on('connections.song_id', '=', 'songs.id')
->join('keywords', 'LEFT')->on('connections.keyword_id', '=', 'keywords.id')
->group_by('songs.id')
->order_by('nconnections')
->as_object('Model_Song')
->execute();
or in SQL
SELECT `songs`.*, COUNT(`keywords`.`id`) AS `nconnections` FROM songs
LEFT JOIN `connections` ON `connections`.`song_id` = `songs`.`id`
LEFT JOIN `keywords` ON `connections`.`keyword_id` = `keywords`.`id`
GROUP BY `songs`.`id` ORDER BY `nconnections`
should return the result you want.
You'll want to have an accessible property called nconnections in your song model. The simplest way to do that is to add a public member so you don't tamper with ORM's inner workings.
I'm assuming you're using a model called 'Song', linked to a 'songs' table, a 'Keyword' model linked to a 'keywords' table and in the 'connections' table foreign keys 'song_id' and 'keyword_id' for each model respectively.