Here is the code I've written: models.py: class Name_overall(models.Model): rank = models.IntegerField() name = models.CharField(max_length=50) frequency = models.IntegerField() def __unicode__(self): return self.name class Name_state(models.Model): gender = models.CharField(max_length=1, choices=GEND...
Is this correct? class Customer(models.Model): account = models.ForeignKey(Account) class Order(models.Model): account = models.ForeignKey(Account) customer = models.ForeignKey(Customer, limit_choices_to={'account': 'self.account'}) I'm trying to make sure that an Order form will only display customer choices that belong...
I have a table of Vendors (Vendor object) where one of the columns is a NULLABLE foreign key reference to my Accounts table (Account object). On my edit form I display the list of Accounts as a dropdown list. I have no problems setting a value nor updating the value to another account. However, I have been unable to clear the value. Eac...
SubSonic SimpleRepository doesn't seem to have a lot of support for foreign relations. How can I have foreign relationships in my code models that persist and load from the database naturally? ...
Hello guys, hope you all had a happy new year. So, my question is, what's the best way to make a log of actions. Let me explain it with a example, suppose we have these entities: User Friend (User is a friend of another User, many to many relationship) Message (An user can message another user) Group (An user can be in various group...
I am not able to save the many to one composite foreign key value. PricingSheetFeeLineItem has one-to-many relation with SaleObjectPricingSheet. saleObjectPricingSheet has composite primary key. When I called session.saveOrUpdate(aPricingSheetFeeLineItem), the value for saleObjectPricingSheet is not able to be caught by hibernate so the...
Hello, I'm getting this error when trying to add a foreign key contraint: #1005 - Can't create table './testtable/#sql-595_146.frm' (errno: 150) I need to do an ON DELETE CASCADE for all images that share a project id when that project is deleted. My simplified table structure is as follows: CREATE TABLE IF NOT EXISTS `images` ( `im...
Hi there, I have following 'comments' table in my app: comments -------- id INT foreign_id INT model TEXT comment_text TEXT ... the idea of this table is to store comments for various parts of my app - it can store comments for blog post i.e: 1|34|blogpost|lorem ipsum... user picture: 2|12|picture|lorem ipsum.....
In the past few years I have read plenty of articles on Foreign Keys in MySQL, nothing recent though. I know they are good to use on something like a forum topic that has child post's under it, if I delete a topic with 100 post's connected to that topic, foreign keys will make it delete those 100 topics for me, am I correct so far? I...
Hi - I am attempting to delete all rows in two dependent tables based on a third tables ID. Table structure: Transaction -Transaction_ID (primary) -Timestamp Purchase -Item_ID -Transaction_ID -Purchase_ID (primary) Item -Item_ID (primary) -Client_ID I would like to delete all rows from transaction/purchase that match the Client_ID...
We're trying to rename a column in MySQL (5.1.31, InnoDB) that is a foreign key to another table. At first, we tried to use Django-South, but came up against a known issue: http://south.aeracode.org/ticket/243 OperationalError: (1025, "Error on rename of './xxx/#sql-bf_4d' to './xxx/cave_event' (errno: 150)") AND Error on ren...
I have a MySQL (5.1.42 on OsX) running. I added a Foreign Key with this sql statement: ALTER TABLE `Portal`.`Mitarbeiter_2_BlackBerry` ADD CONSTRAINT `fk_Blackberry` FOREIGN KEY (`id` ) REFERENCES `Portal`.`Blackberry` (`id` ) ON DELETE NO ACTION ON UPDATE NO ACTION , ADD INDEX `fk_Blackberry` (`id` ASC) But when i try to i...
Hi, I had a problem with the method Doctrine_Table::find(), since it's thorowing an exception of SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens I solved the problem by using Doctrine::getTable('City')->findOneById($id); instead and it works fine. When I tried to invistigate about t...
I am currently thinking about the database design of a 'friends' table (many-to-many, stores the friendships between users). Columns: user_id friend_id Does it make sense to prefer a multi-column primary key instead of an additional 'friendship_id' column? If so, can I add Foreign Keys for both columns? ...
What's the more accepted Rails approach? Validate that a foreign key exists on creation/update or "Damage control" when we want to use the non-existent foreign key? Initial validation requires more resources on row creation/updating, and may even be redundant when I'm creating rows systematically in my code (i.e. not user generated)....
Some introduction. I have a "planet-like" feed aggregator with an extra layer on top. That extra layer allows for comments and elaboration on the aggregated posts. Here's some code for reference. class Post(models.Model): title = models.CharField() published = models.DateTimeField() class Story(models.Model): title = models...
I'm sure this is a very simple question, but I'm just a newbie so... I have a model, Game, which has_many :piles. Pile, in turn, has_many :cards. I'm able to populate the Piles and Cards at creation of the Game, so my code at present looks something like: class Game < ActiveRecord::Base has_many :piles def after_create 1.upto(...
Hai guys, I have two tables Incharge and property. My property table has three fields 1stIncharge,2ndIncharge and 3rdIncharge. InchargeId is set as foreign key for all the above fields in the property table.. How to write a select statement that joins both the table.. I ve tried a bit but no result select P.Id,P.Name,P.1stIncharge,P....
I used an online SQL builder to help design some MySQL tables I'm working on. Foreign keys always confuse me. The code I came up with tries to add these 4 foreign keys but I want to make sure that I want them before I add them. ALTER TABLE `users` ADD FOREIGN KEY (user_id) REFERENCES `settings` (`user_id`); ALTER TABLE `logins` ADD ...
Django doesn't support getting foreign key values from list_display or list_filter (e.g foo__bar). I know you can create a module method as a workaround for list_display, but how would I go about to do the same for list_filter? Thanks. ...