Putting the database model into a class library in. Net Core

I. Summary of Prerequisites

One day this year suddenly bored, decided to learn. NET core, the version is now. NET Core 1.1. has been using the. NET Framework to do projects, has been on the html.editfor () and other HTML Helper, feeling the flexibility is too poor, this time after looking at Microsoft Docs document, feel the power of. NET core, especially tag Helper, decided to plunge into the platform, but found a problem in the new project: the previous project was to put the database model in a separate class library, but now found that the. NET Core Class library configuration is not the same, there is always a problem, so began to use the international version of Bing (by the way despise the next degree) search information, Searching for answers in the issues and Stackoverflowk of the ASPNET project group at GitHub has finally found a solution.

Ii. references

https://docs.microsoft.com/en-us/ef/core/miscellaneous/cli/dotnet# targeting-class-library-projects-is-not-supportedhttps://docs.microsoft.com/en-us/ef/core/miscellaneous/ Configuring-dbcontext
http://benjii.me/2016/06/entity-framework-core-migrations-for-class-library-projects/
https://github.com/aspnet/EntityFramework/issues/5320

Iii. Concrete Solutions 1. The new. NET core Web application is named TestMigrationInClassLibrary2, a new. NET Core class library is called NetDomain3, testmigrationinclasslibrary Reference NEtDomain4, in NThe following steps are performed in the Etdomain Class Library: (1) Add Microsoft.EntityFrameworkCore.Tools.DotNet in *.csproj

< ItemGroup >    <  Include= "Microsoft.EntityFrameworkCore.Tools.DotNet"  Version= "1.0.0"  />  </ItemGroup>

(2) Add package Microsoft.EntityFrameworkCore.Design

Using the CMD controller, enter the class Library folder directory using the following command

dotnet Add Package Microsoft.EntityFrameworkCore.Design

The final style of *.csproj after adding these two prerequisites is as follows:

<ProjectSDK= "MICROSOFT.NET.SDK">  <PropertyGroup>    <OutputType>Exe</OutputType>    <targetframework>netcoreapp1.1</targetframework>  </PropertyGroup>  <ItemGroup>    <packagereferenceInclude= "Microsoft.EntityFrameworkCore.Design"Version= "1.1.1"privateassets= "All" />  </ItemGroup>  <ItemGroup>    <dotnetclitoolreferenceInclude= "Microsoft.EntityFrameworkCore.Tools.DotNet"Version= "1.0.0" />  </ItemGroup></Project>

(3) Installing SQL Server with NuGet

Install-package Microsoft.EntityFrameworkCore.SqlServer

(4) Add model

 Public class Course    {        publicintgetset;}          Public string Get Set ; }          Public string Get Set ; }    }

(5) Add DbContext

 Public class Coursedbcontext:dbcontext    {        publicbase(options)        {        }        publicget Set ; }    }

(6) Add Contextfactory

 Public classCoursedbcontextfactory:idbcontextfactory<coursedbcontext>    {         Publiccoursedbcontext Create (dbcontextfactoryoptions options) {varOptionsbuilder =NewDbcontextoptionsbuilder<coursedbcontext>(); Optionsbuilder.usesqlserver ("server= (LocalDb) \\mssqllocaldb;database=testclasslibrary; Trusted_connection=true; Multipleactiveresultsets=true"); return NewCoursedbcontext (optionsbuilder.options); }    }

5. Use the following command to open migration in the directory where the class library is located

Dotnet EF--startup-project. /testmigrationinclasslibrary migrations Add initial-c coursedbcontext

Be aware of the ".. /testmigrationinclasslibrary "is a class library of the entry project, without this entrance, is unable to start migration.

6. Update the database

dotnet EF Database Update--startup-project. /testmigrationinclasslibrary

Also need to add entry engineering Testmigrationinclasslibrary

Iv. Summary

Because the. NET Core class library does not have the same startup functionality as the. NET Standard class library, you must designate other bootable projects as portals, so each time the migration is added "--startup-project XXX".

In order to be able to separate the database model, it still takes a lot of effort, but the other advantages of. NET core are far better than traditional. Net. To get started. NET core, it is recommended to look at Microsoft's official docs and go to GitHub to fork the entire source code.

Putting the database model into a class library in. Net Core