edmx

问题 I think I have CodeFirst understood. Now I know database first EF design is targeted for existing databases, but if I were to quickly go in and create a new database in management studio and create some tables, is it normal that you would create relationships for the tables in management studio or in the edmx designer, I tried in the edmx but got errors when I went to debug. What is the best practice here and what are the correct steps to create Associations between tables if I were to do it

问题 Majority of our tables in our models has a field called "intConcurrencyID" that we intended to use for concurrency checking. I believe the only way to enable this field for concurrency checking in a Database First environment is to set the Concurrency Mode to Fixed. However, if we have huge numbers of tables per EDMX, we will have a hard time manually configuring each type per entity not to mention the possibility of some entities to be overlooked. Do you have any ideas on how I can automate

问题 I am having a difficult time resolving a silly mapping problem. Basically what is going on is that I have a field in a sql db table that is a varbinary for the purposes of security (encryption and decryption). All that stuff is all well and good but it seems as though the edmx sees the field in that table as a string which I thought it should see it as given that the data is just a binary string. This is the error message I get. Schema specified is not valid. Errors: ReadModel.Model.msl(836

问题 I'm a beginner to Entity Framework . I notice that When I use EF6 with Visual studio 2013 : I have .Designer.cs empty file with this comment: // T4 code generation is enabled for model 'C:\Users\Luka\Desktop\Test\EF-db2008\AdventureWorks\AdventureWorksLib\AdventureWorksLib\AWLTModel.edmx'. // To enable legacy code generation, change the value of the 'Code Generation Strategy' designer // property to 'Legacy ObjectContext'. This property is available in the Properties Window when the model //

问题 I am having trouble creating a new edmx file using Visual Studio 2011 beta Target framework .Net 4.5 Class library project After adding an empty model I get the error below Error 6039: warning CS1701: Assuming assembly reference 'System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' matches 'System.Data.Entity, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089', you may need to supply runtime policy \fjwflppr.0.cs(465,29) : error CS1061:

问题 I like to to keep my code first - or T4 generated - POCOs in a project separated from the DbContext. This helps me ensure my entity classes aren't coupled to any one data access service. When I create a new DB first EDMX model, the wizard generates a T4 template to generate all the POCOs in the same project as the DbContext. How can I modify this template to add classes to a separate project? On closer inspection, it would probably be much easier to move the DbContext to a new project, but

问题 I've created an EDMX object from a database I'm programming against. I need to get input from a user and save it to a row in the database table. The problem is that I need to limit the length of input strings to the width of the corresponding VARCHAR column in the database. When I browse the model, I can clearly see in the properties window that the model knows the max length of the string, but I don't know how to access this data in code. If I want to write something like this: Entities

问题 I am using a databse first method. I generated edmx from the database. But diagrams for the tables which are in many to many relationships do not display in the generated edmx. 回答1: If your Many to many lookup table consists of just Foreign Keys and no other fields, then it will not show up in your edmx file as a Table. It will show up under Navigation Properties of each table though. 来源： https://stackoverflow.com/questions/7544259/the-diagram-for-the-many-to-many-relationship-table-does-not

问题 I am currently generating some code from an edmx file with a t4 template by going through all of the properties. By default the edmx file has navigation properties that are named after the object type essentially but I would like to change it to work off of the foreign key id column instead. For example there is a Region table which is referred to by a single table twice - it has both a Supervisory Region and a Geographic Region. The default edmx navigation property name is Region and Region1

问题 Below are my 2 class sharing 1 to many relationship : public partial class Employee { public int Id { get; set; } public string Name { get; set; } public virtual ICollection<Skills> Skills { get; set; } } public partial class Skills { public int Id { get; set; } public Nullable<int> EmployeeId { get; set; } public string Skills { get; set; } public virtual Employee Employee { get; set; } } Now I am trying to remove employees with its corresponding skills in following way : 1) Deleting both