composite-primary-key

I have an entity where the primary key consists of two foreign keys to two other tables. I have the configuration working with the following but the table is generated with two FK references. The table: domain.Entity1 MorePK (PK, FK, int, not null) Entity2_Id (PK, FK, int, not null) Entity3_Id (PK, FK, int, not null) OtherData (varchar, null) Entity2_Id1 (FK, int, null) Entity3_Id1 (FK, int, null) is generated from: public Entity1 { public int MorePK { get; set; } public int Entity2_Id { get; set; } public int Entity3_Id { get; set; } public string OtherData { get; set; } public virtual

I'm in a situation where I have a table called Elements . Now I'm creating a table called Divergences that will store basically pairs of Elements . The purpose of Divergence is to check if two Elements have diverging answers. Element Divergence --------- ---------- ElementId ElementId1 ElementId2 In the above table schema, ElementId1 and ElementId2 are Foreign Keys mapping to ElementId in Elements table and form the composite primary key for the Divergence table. I use Database First approach where I create the tables in SQL Server Management Studio and later I do a Update Model from Database.

I'm curious about how Entity Framework and MVC scaffolding handle primary keys. When I create a controller in an MVC3 project and choose the scaffolding template of 'Controller with read/write actions and views, using Entity Framework' and specify my model a controller is generated that uses one primary key. My entity has 2 keys which are needed to pull data correctly. I made the necessary adjustments manually but I wanted to make sure I understand this properly before moving forward. My thinking is that when Microsoft implemented this pattern they thought support for one primary key would be

i am working on mysql server.where i have created a table, named question . column/attributes of this table are (course,subject,year,question) i want to create a primary key(or composite key) consists of (course+subject+year). i.e. for a particular course+subject+year combination there can be only one question.there will be only one row with the combination of (course+subject+year),creation of another row won't be possible. i have done it by : primary key(course,subject,year); but it's not working.still i can create two rows with same combination of course,subject,year. can anyone tell me how

I am trying to map a composite key for an entity. public class Customer { public int CustomerId { get; set; } public virtual List<CustomerImage> CustomerImages { get; set; } } And its Map: public class CustomerMap : EntityTypeConfiguration<Customer> { public CustomerMap() { HasKey(t => t.CustomerId); ToTable(DbConstants.k_CustomersImageTable); } } An Image: public class Image { public int ImageId { get; set; } } And its map: public class ImageMap : EntityTypeConfiguration<Image> { public ImageMap() { HasKey(t => t.ImageId); ToTable(DbConstants.k_ImagesTable); } } And the navigation property:

I am having issues with hydrating a class which consists of a composite ID which in turn has a base class, I am getting an error saying InvalidOperationException: {document}.Identity is not supported. The class i am trying to write to the database is below: public class Product : IEntity<Product> { public readonly Sku Sku; public string Name { get; private set; } public string Description { get; private set; } public bool IsArchived { get; private set; } public Identity<Product> Identity => Sku; public Product(Sku sku, string name, bool isArchived) { Sku = sku; Name = name; IsArchived =

I am using log-error to write warning/errors into a file. When I perform INSERT IGNORE..SELECT statement, it just keep write this warning messages. 120905 3:01:23 [Warning] Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT. INSERT IGNORE... SELECT is unsafe because the order in which rows are retrieved by the SELECT determines which (if any) rows are ignored. This order cannot be predicted and may differ on master and the slave. I want to stop mysql logwriter keep writing the error above over and over. (I can't see other log because they fillout