A simple database access layer based on EntityFramework core for lightweight database services

The code of this access layer is actually a senior in the garden, I just feel so, recorded down.

This access layer requires the installation of EntityFramework Core through NuGet, but the individual believes that EF 6 is also available.

collocation database, preferably SQL Server (Microsoft Support, you understand)

Paste the following code

First IRepository.cs.

Public interface irepository:idisposable    {    
Gets a table of iquerable interface queries            iqueryable<t> all<t> () where t:class;
Insert a record        void insert<t> (T entity) where T:class;
According to the conditions, obtain a record        T get<t> (expression<func<t, bool>> conditions) where t:class;
Pass in a previously obtained T object, modify the record                void update<t> (t entity) where T:class;
Delete a record        void delete<t> (T entity) where T:class;
Save all Changes        int SaveChanges ();    }

Then the realization of Repository.cs

　　public class Repository:irepository {private DbContext context;        Public Repository (DbContext DbContext) {context = DbContext; } public iqueryable<t> all<t> () where T:class {return context. Set<t> ().        Asnotracking (); The public void insert<t> (T entity) where T:class {context. Set<t> ().        ADD (entity); } public T get<t> (expression<func<t, bool>> conditions) where T:class {retur n all<t> ().        FirstOrDefault (conditions); The public void update<t> (T entity) where T:class {var entry = context.            Entry (entity); if (entry. state = = entitystate.detached) {context. Set<t> ().            Attach (entity); } entry.        state = entitystate.modified;      } public void delete<t> (T entity) where T:class {      var entry = context.            Entry (entity); if (entry. state = = entitystate.detached) {context. Set<t> ().            Attach (entity); } entry.        state = entitystate.deleted; } public int SaveChanges () {return context.        SaveChanges (); public void Dispose () {context.        Dispose (); }    }

Specific use:

You can write a dbfactory method that is used to generate a database connection (object)

public class Dbfactory    {       //There may be a database connection string or something, the specific application of public        static IRepository Create ()        {            return New Repository (New Dbfactory (). DbContext);        }    }

At the business logic level, we can

using (var db = Dbfactory.create ())       {/           /here can be additions and deletions of code,           //  db, for example. Insert<user> (User);  Db. Insert<userother> (UO);
  can be arbitrarily cross-table, EntityFramework own transactions, and finally savechanges will be processed together
           int result = db. SaveChanges ();       SaveChanges () Returns a change number, so you can view the result with a number of type int.       }        

A simple database access layer based on EntityFramework core for lightweight database services