5. Data access - entityframework integration

Preface

Masa

Provides the basis for

EntityFramework

Data integration for , It also provides the functions of data filtering and soft deletion , Now we will introduce how to use it ？

MasaDbContext introduction

• install
  .Net 6.0

• newly build ASP.NET Core  Empty item
  Assignment.MasaEntityFramework
  , And install
  Masa.Contrib.Data.EntityFrameworkCore
  、
  Swashbuckle.AspNetCore
  、
  Microsoft.EntityFrameworkCore.InMemory
  、
  Microsoft.EntityFrameworkCore.Tools

 dotnet add package Masa.Contrib.Data.EntityFrameworkCore --version 0.4.0-rc.4
 dotnet add package Swashbuckle.AspNetCore --version 6.2.3
 dotnet add package Microsoft.EntityFrameworkCore.InMemory --version 6.0.5
 dotnet add package Microsoft.EntityFrameworkCore.Tools --version 6.0.5

>  install `Swashbuckle.AspNetCore` For the convenience of passing `Swagger` To operate the service
>  install `Microsoft.EntityFrameworkCore.InMemory` It's for convenience , So use an in memory database , If you need to use other databases , Please install the corresponding package by yourself
>  install `Microsoft.EntityFrameworkCore.Tools` To use CodeFirst Create database


• The new class
  User

 public class User
 {
 public int Id { get; set; }
 
 public string Name { get; set; }
 
 public uint Gender { get; set; }
 
 public DateTime BirthDay { get; set; }
 
 public DateTime CreationTime { get; set; }
 
 public User()
 {
 this.CreationTime = DateTime.Now;
 }
 }


• New user context
  UserDbContext.cs

 public class UserDbContext : MasaDbContext
 {
 public DbSet<User> User { get; set; }
 
 public UserDbContext(MasaDbContextOptions options) : base(options)
 {
 }
 }

> `UserDbContext` Instead of inheritance `MasaDbContext`,  And add a parameter constructor , Parameter type is `MasaDbContextOptions`
>  When there are multiple DbContext when , It needs to be inherited `MasaDbContext<TDbContext>`, The constructor parameter type is changed to `MasaDbContext<TDbContext>`


• The new class
  AddUserRequest
  As a parameter for adding users

 public class AddUserRequest
 {
 public string Name { get; set; }
 
 public uint Gender { get; set; }
 
 public DateTime BirthDay { get; set; }
 }


• The new class
  HostExtensions
  For migrating databases （ Use CodeFirst）

 public static class HostExtensions
 {
 public static void MigrateDbContext<TContext>(
 this IHost host, Action<TContext, IServiceProvider> seeder) where TContext : DbContext
 {
 using (var scope = host.Services.CreateScope())
 {
 var services = scope.ServiceProvider;
 var context = services.GetRequiredService<TContext>();
 context.Database.EnsureCreated();
 seeder(context, services);
 }
 }
 }


• modify
  Program.cs
  , newly added
  Swagger
  Support

 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();

 var app = builder.Build();

 app.UseSwagger();
 app.UseSwaggerUI();


Unwanted

Swagger

Don't add , Use Swagger Just to test and invoke the service , Use

Postman

Or something else Http Tools can also

• modify
  Program.cs
  , Add user context （ a key ）

 builder.Services.AddMasaDbContext<UserDbContext>(options => 
 {
 options.Builder = (_, dbContextOptionsBuilder) => dbContextOptionsBuilder.UseInMemoryDatabase(&quot;test&quot;)
 });


• modify
  Program.cs
  , Make the project support CodeFirst

 app.MigrateDbContext<UserDbContext>((context, services) =>
 {
 });

>  Unwanted CodeFirst, Code generation is not supported, and the database cannot be added


• test
  MasaDbContext
  , modify
  Program.cs

 app.MapPost("/add", (UserDbContext dbContext, [FromBody] AddUserRequest request) =>
 {
 dbContext.Set<User>().Add(new User()
 {
 Name = request.Name,
 Gender = request.Gender,
 BirthDay = request.BirthDay
 });
 dbContext.SaveChanges();
 });
 
 app.MapGet(&quot;/list&quot;, (UserDbContext dbContext) =>
 {
 return dbContext.Set<User>().ToList();
 });

>  Run the project by yourself , perform `add` Then create a new user , After performing `list` Get more than one user data , Then prove `MasaDbContext` Correct use


How to use soft delete

• Choose
  Assignment.MasaEntityFramework
  And install
  Masa.Contrib.Data.Contracts.EF

 dotnet add package Masa.Contrib.Data.Contracts.EF --version 0.4.0-rc.4


• Modify the class
  User
  , And implement
  ISoftDelete
  , Change the code to ：

 public class User : ISoftDelete// a key ： Change to implementation ISoftDelete
 {
 public int Id { get; set; }
 
 public string Name { get; set; }
 
 public uint Gender { get; set; }
 
 public DateTime BirthDay { get; set; }
 
 public DateTime CreationTime { get; set; }
 
 public bool IsDeleted { get; private set; }
 
 public User()
 {
 this.CreationTime = DateTime.Now;
 }
 }

>  Increase implementation `ISoftDelete`, And for `IsDeleted` Attribute addition set Support （ It can be private set;）


• modify
  Program.cs
  , And enable data filtering

 builder.Services.AddMasaDbContext<UserDbContext>(options =>
 {
 options.Builder = (_, dbContextOptionsBuilder) => dbContextOptionsBuilder.UseInMemoryDatabase(&quot;test&quot;);
 options.UseFilter();// Enable data filtering , Complete writing ：options.UseFilter(filterOptions => filterOptions.EnableSoftDelete = true);
 });


• Test whether the soft deletion is successful

• modify
  Program.cs
  , Add delete method

 app.MapDelete("/delete", (UserDbContext dbContext, int id) =>
 {
 var user = dbContext.Set<User>().First(u => u.Id == id);
 dbContext.Set<User>().Remove(user);
 dbContext.SaveChanges();
 });


Last , First call

add

Method after creating the user , Call later

list

Method to get the list of all users , And take out any one id Information , Then call

delete

Method to delete the user , Last call

list

Method , View removed id Whether there is , To verify whether the soft deletion is effective .

How to temporarily disable soft deletion filtering

In the default query, the data marked with deleted tags will be filtered and no longer be queried , But there are also some scenarios that need to query all the data , At this point, you need to use data filtering

IDataFilter

• newly added
  All
  Method is used to query all data （ Contains data marked as deleted ）

 app.MapGet("/all", (UserDbContext dbContext, [FromServices] IDataFilter dataFilter) =>
 {
 // adopt DI Get IDataFilter, And call it Disable Method can be temporarily disabled ISoftDelete filter
 using (dataFilter.Disable<ISoftDelete>())
 {
 return dbContext.Set<User>().ToList();
 }
 });


• Rerun the project , Repeat the steps of verifying soft deletion , Make sure to pass
  list
  Method cannot access data

• The reason for repeating the verify soft delete step is that this example uses an in memory database , After the project stops , All data will be cleared , Re execution is to ensure that the data exists , Only marked for deletion

• perform
  all
  Method , Get all the data , see id Whether the corresponding user data exists

Get the database connection string from the configuration file

• Selected items
  Assignment.MasaEntityFramework
  , And install
  Masa.Contrib.Data.EntityFrameworkCore.InMemory

 dotnet add package Masa.Contrib.Data.EntityFrameworkCore.InMemory --version 0.4.0-rc.4

>  Install the corresponding database package as needed , Such as ：`Masa.Contrib.Data.EntityFrameworkCore.SqlServer` (SqlServer)、`Masa.Contrib.Data.EntityFrameworkCore.Pomelo.MySql` (Pomelo Provided MySql)、`Masa.Contrib.Data.EntityFrameworkCore.Oracle` (Oracle) etc.


• modify
  Program.cs
  , Adjust the configuration of adding user context to :

 builder.Services.AddMasaDbContext<UserDbContext>(options => options.UseInMemoryDatabase().UseFilter());


• modify
  appsettings.json
  , Add user database connection string :

 {
 "ConnectionStrings": {
 "DefaultConnection": "test"// Replace with the specified database connection string
 }
 }


• modify
  Program.cs
  , newly added
  database
  Method , Verify that the current database is
  test

 app.MapGet("/database", (UserDbContext dbContext) =>
 {
 var field = typeof(MasaDbContext).GetField("Options", BindingFlags.Public | BindingFlags.Instance | BindingFlags.NonPublic)!;
 var masaDbContextOptions = field.GetValue(dbContext) as MasaDbContextOptions;
 foreach (var dbContextOptionsExtension in masaDbContextOptions!.Extensions)
 {
 if (dbContextOptionsExtension is InMemoryOptionsExtension memoryOptionsExtension)
 {
 return memoryOptionsExtension.StoreName;
 }
 }
 
 return "";
 });


Last visit

http://localhost:5002/database

, Verify whether the current database name is consistent with the modified database name

common problem

• How to change the default read configuration node ?

• Modify user context
  UserDbContext
  And increase
  ConnectionStringName
  characteristic :

 [ConnectionStringName("User")]// Custom node name
 public class UserDbContext : MasaDbContext
 {
 public DbSet<User> User { get; set; }
 
 public UserDbContext(MasaDbContextOptions options) : base(options)
 {
 }
 }


• Modify the configuration
  appsettings.json

 {
 "ConnectionStrings": {
 "User": "test"// Instead of from User The node reads the database connection string
 }
 }


• In addition to getting from the configuration file , Does it also support getting database connection strings from other places ？

There are currently two ways to change the database connection string .

Method 1:  modify

Program.cs

, And delete

appsettings.json

Configuration of database connection string

• modify
  Program.cs

 builder.Services.Configure<MasaDbConnectionOptions>(option =>
 {
 option.ConnectionStrings = new ConnectionStrings(new List<KeyValuePair<string, string>>()
 {
 new(&quot;User&quot;, &quot;test2&quot;)// Where the key is the node name , And ConnectionStringName Characteristic Name Keep the values consistent , If not specified ConnectionStringName, It should be DefaultConnection, The value is the database connection string
 });
 });


• modify
  appsettings.json
  To configure

 // "ConnectionStrings": {
 // "User": "test"
 // },


• call
  database
  Method , Verify whether the current database is
  test2

Method 2:  rewrite

IConnectionStringProvider

and

IDbConnectionStringProvider

And add to DI in

• The new class
  CustomizeConnectionStringProvider

 public class CustomizeConnectionStringProvider : IConnectionStringProvider
 {
 public Task<string> GetConnectionStringAsync(string name = &quot;DefaultConnection&quot;) => Task.FromResult (GetConnectionString(name));
 
 public string GetConnectionString(string name = &quot;DefaultConnection&quot;) => &quot;test3&quot;;
 }


• The new class
  CustomizeDbConnectionStringProvider

 public class CustomizeDbConnectionStringProvider : IDbConnectionStringProvider
 {
 public List<MasaDbContextConfigurationOptions> DbContextOptionsList { get; } = new()
 {
 new MasaDbContextConfigurationOptions(&quot;test3&quot;)
 };
 }


• modify
  Program.cs

 builder.Services.AddSingleton<IConnectionStringProvider,CustomizeConnectionStringProvider>();
 builder.Services.AddSingleton<IDbConnectionStringProvider,CustomizeDbConnectionStringProvider>();


• call
  database
  Method , Verify whether the current database is
  test3

• 

summary

This article mainly explains

MasaDbContext

Basic usage and soft deletion 、 How to use data filtering , In the next article, we will explain

MasaDbContext

How to realize soft deletion 、 Data filtered , And how to realize it when using the database without specifying the database link string mentioned in this article

Source code of this chapter

Assignment05

https://github.com/zhenlei520/MasaFramework.Practice

Open source address

MASA.BuildingBlocks：https://github.com/masastack/MASA.BuildingBlocks

MASA.Contrib：https://github.com/masastack/MASA.Contrib

MASA.Utils：https://github.com/masastack/MASA.Utils

MASA.EShop：https://github.com/masalabs/MASA.EShop

MASA.Blazor：https://github.com/BlazorComponent/MASA.Blazor

If you treat our  MASA Framework  Interested in , Whether it's code contribution 、 Use 、 carry  Issue, Welcome to contact us