foreign-keys

SQL Server 2005 - Foreigh Keys with Cascaded Delete

Is there a way around this in SQL Server 2005? (It bugs me, and every time I encounter it I get in to a strop. But this is the first time I've had to deal with AND been on Stack Overflow. Please, save what little sanity I posess!) DimensionTable: id INT IDENTITY(1,1) FactTable: source_id INT NOT NULL, target_id INT NOT NULL I...

nhibernate Composite Foregin key

People, I have a horrible legacy DB that i have to map in nHibernate, that im not allowed to change. There is a horrible tree structure called FaultCodes with these fields: ID int eventID int treeID int (unique per eventID) parentTreeID int ID is the PK, its used by other tables to join to this one. Problem is, the parent/child r...

Ruby on Rails. How do I use the Active Record .build method in a :belongs to relationship?

I have been unable to find any documentation on the .build method in Rails. (I am currently using 2.0.2) Through experimentation it seems you can use the build method to add a record into a :has_many relationship before either record has been saved. for example Class Dog :has_many :tags :belongs_to :person end Class Person :h...

SQL Pivot for foreign key column

I have a table like so: Fiscal Year, Region, Country, Office1, Office2, Office3, Office4 Where office 1-4 are foreign keys. I would like to get output like so: Office 1: Fiscal Year, Region, Country Office 2: Fiscal Year, Region, Country Office 3: Fiscal Year, Region, Country Office 4: Fiscal Year, Region, Country Can this be done usi...

Composite foreign key columns in GORM

Hi, I need to customize the column names for composite foreign keys in GORM, and I didn't find any document that shows how to do it. I know how to customize PK columns, and how to customize a single-column FK, but not multi-column FK. Is it possible at all? Thanks. ...

Changing a record in a table (sql server) that has foreign keys?

Hi there, Does anyone know if there is a quicker way of editing a record that has foreign keys in a table (in sql server).. i will explain.. i have approx 5 tables that have there own ID but are linked together using a foreign key... Hence i needed to change the foreign key (the contract number in my case), but i had to copy each recor...

Sorting by foreign key values in GridView with Entity Framework?

When using GridView's built in Sorting with Entity Framework, I can display foreign key values. For example... <asp:boundfield HeaderText="Category" DataField="Category.Name" SortExpression="Category.Name" /> ...but when the header is clicked to sort the items in the grid, how can I sort my List list by Category.Name? I only have th...

Introducing FOREIGN KEY constraint 'c_name' on table 't_name' may cause cycles or multiple cascade paths.

I have a database table called Lesson: columns: [LessonID, LessonNumber, Description] ...plus some other columns I have another table called Lesson_ScoreBasedSelection: columns: [LessonID,NextLessonID_1,NextLessonID_2,NextLessonID_3] When a lesson is completed, its LessonID is looked up in the Lesson_ScoreBasedSelection table to get th...

How do I update an object's foreign key value with LINQ to Entities?

Suppose I have these tables: Fruits - FruitID INT PK - FruitName NVARCHAR(30) - FruitStatusID INT FK: Statuses Statuses - StatusID INT PK - StatusName NVARCHAR(30) How do I update both the Fruit's name and its status in the database in these situations?: Update a piece of Fruit that came from a previous L2E c...

MySQL change type of foreign key

I am using MySQL and I have a table with an index that is used as a foreign key in many other tables. I want to change the data type of the index (from signed to unsigned integer) , what is the best way to do this? I tried altering the data type on the index field, but that fails because it is being used as a foreign key for other table...

Query to get all foreign key constraints in SqlServer 2000

Title says it all. I need a query for SqlServer 2000 to get a list of all foreign keys. Additional info: Whoops I guess the title doesn't say it all. I meant to add "that point to a particular column" ...

DataGridView and DataSource: Any way to display fields linked to by foreign keys easily?

I have a three-tier Windows Forms DB application in VB.NET. I'm using VS 2005. I'd like to display records in a table in a DataGridView. I can already display the records as is by binding the DataSource to the business class that talks to the DB class: Dim assetList as List(Of Asset) assetList = DB_Asset.GetAssetListOrderByID_Asset ...

MySQL Removing Some Foreign keys

I have a table whose primary key is used in several other tables and has several foreign keys to other tables. CREATE TABLE location ( locationID INT NOT NULL AUTO_INCREMENT PRIMARY KEY ... ) ENGINE = InnoDB; CREATE TABLE assignment ( assignmentID INT NOT NULL AUTO_INCREMENT PRIMARY KEY, locationID INT NOT NULL, FOREIGN...

Create Foreign Key SQL

How do I create a foreign key from table tGeoAnswers column 'locationId' to table tLocations column 'id'? ALTER TABLE tGeoAnswers ADD FK_Answer_Location FOREIGN KEY (locationId) REFERENCES tLocations(id) I am trying this code that I found but I get the following error: The definition for colu...

How to anonymize new log records without breaking relations between old and new data?

I am generating log records about user actions. For privacy reasons, these need to be anonymized after N days. However, I also need to run reports against this anonymized data. I want all actions by real user A to be listed under fake user X in the anonymized logs - records of one user must still remain records of one (fake) user in the...

A way to check if foreign key exists in SQL 2005

Is there an easy way to check if a foreign key exists for a column in a table? I am writing a script which will add the foreign key only if it does not exist. Thanks ...

How to prevent self (recursive) selection for FK / MTM fields in the Django Admin

Given a model with ForeignKeyField (FKF) or ManyToManyField (MTMF) fields with a foreignkey to 'self' how can I prevent self (recursive) selection within the Django Admin (admin). In short, it should be possible to prevent self (recursive) selection of a model instance in the admin. This applies when editing existing instances of a mod...

Changing a column in oracle that has a foreign key constraint

I have a column that is only 6 characters long in a table that references a column that is 20 characters using a foreign key constraint. How do I fix this? Note: The issue was due to the limitation of the Oracle SQL Developer Edit table. When I performed the specific alter column, it worked fine. ...

How to use dynamic foreignkey in Django ?

hey, i want to use 2 model in one foreignkey it means; i have 2 model named screencasts and articles. and i have a fave model, for favouriting this model entrys. can i use model dynamicly ? class Articles(models.Model): title = models.CharField(max_length=100) body = models.TextField() class Casts(models.Model): title = ...

How to determine where to place the foreign key in this scenario?

If I have two tables - Logins and Users, as follows: Logins LoginIdNo UserIdNo HashedPassword Users UserIdNo LoginIdNo Username Each login "has a user" and each user "has a login" but which "belongs to" which? Is it simply a judgment call or is there a clearcut formula for determining where the foreign key should reside? ...