Abp vNext+SqlServer+MySqlServer

目前项目使用的是 ABP vNext 版本 8.2.0 加上 SQL Server。由于业务需求，我们需要与 MySQL 数据库进行对接，这意味着项目的主要功能将继续使用 SQL Server，而部分特定功能将需要与 MySQL 数据库交互。

步骤1. 在项目“XXX.XXX.EntityFrameworkCore”中安装MySql包

dotnet add package Volo.Abp.EntityFrameworkCore.MySql
dotnet add package Pomelo.EntityFrameworkCore.MySql

步骤 2: 配置连接字符串

 在 appsettings.json 文件中添加 MySQL 的连接字符串

{
  "ConnectionStrings": {
    "Default": "Server=(localdb)\\mssqllocaldb;Database=AbpDb;Trusted_Connection=True;MultipleActiveResultSets=true",
    "MySql": "Server=localhost;Port=3306;Database=mydatabase;Uid=myusername;Pwd=mypassword;"
  },
  ...
}

步骤 3: 创建 DbContext

    public class MySqlDbContext : AbpDbContext<MySqlDbContext>
    {
        public MySqlDbContext(DbContextOptions<MySqlDbContext> options)
            : base(options)
        {

        }

        public DbSet<AppStudent> AppStudents { get; set; }

        protected override void OnModelCreating(ModelBuilder builder)
        {
            base.OnModelCreating(builder);

            builder.Entity<AppStudent>(b =>
            {
                b.ToTable("AppStudent");
                b.ConfigureByConvention();
            });
        }
    }

步骤 4: 注册 DbContext

在“XXXX.XXX.EntityFrameworkCore”中找到“XXXXEntityFrameworkCoreModule”

    public override void ConfigureServices(ServiceConfigurationContext context)
    {
        var configuration = context.Services.GetConfiguration();
        context.Services.AddAbpDbContext<TwinsDbContext>(options =>
        {
            /* Remove "includeAllEntities: true" to create
             * default repositories only for aggregate roots */
            options.AddDefaultRepositories(includeAllEntities: true);
        });

        context.Services.AddDbContext<MySqlDbContext>(options =>
        {
            options.UseMySql(
                configuration.GetConnectionString("MySql"),
                ServerVersion.AutoDetect(configuration.GetConnectionString("MySql")));
        });

        Configure<AbpDbContextOptions>(options =>
        {
            /* The main point to change your DBMS.
             * See also TwinsMigrationsDbContextFactory for EF Core tooling. */
            options.UseSqlServer();
        });
    }

步骤 5: 使用 DbContext

    public class AppStudent: Entity<int>
    {
        public virtual string Name{ get; set; }
        public virtual int Age{ get; set; }
    }

    public interface IAppStudentRepository : IRepository<AppStudent, int>
    {
        Task<List<AppStudent>> GetByNameAsync(string name);
    }

  public class AppStudentRepository : EfCoreRepository<MySqlDbContext, AppStudent, int>, 
  {
      public AppStudentRepository(IDbContextProvider<MySqlDbContext> dbContextProvider) : base(dbContextProvider)
      {
      }
      public async Task<List<AppStudent>> GetByNameAsync(string name)
      {
          var dbSet = await GetDbSetAsync();
          return dbSet.AsEnumerable().Where(c => c.Name== name).ToList();
      }
  }