Question

我有两个共享相同存储库的DbContext。以下是我现有的代码：

Startup.cs

        services.AddDbContext<SgAesMasterContext>(options =>  options.UseSqlServer(Configuration.GetConnectionString("SgAesMasterContext"),
            b => b.UseRowNumberForPaging()), ServiceLifetime.Scoped);

        services.AddDbContext<MyAesMasterContext>(options => options.UseSqlServer(Configuration.GetConnectionString("MyAesMasterContext"),
            b => b.UseRowNumberForPaging()), ServiceLifetime.Scoped);

DbContext.cs

public class SgAesMasterContext : DbContext
{
    public DbSet<Company> Companies { get; set; }

    public SgAesMasterContext(DbContextOptions<SgAesMasterContext> options) : base(options) { }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
    }
}

public class MyAesMasterContext : DbContext
{
    public DbSet<Company> Companies { get; set; }

    public MyAesMasterContext(DbContextOptions<MyAesMasterContext> options) : base(options) { }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
    }
}

UnitOfWork.cs

public class AesMasterUnitOfWork: IAesMasterUnitOfWork
{
    private readonly SgAesMasterContext sgAesMasterContext;
    private readonly MyAesMasterContext myAesMasterContext;

    public AesMasterUnitOfWork(SgAesMasterContext sgAesMasterContext, MyAesMasterContext myAesMasterContext)
    {
        this.sgAesMasterContext = sgAesMasterContext;
        this.myAesMasterContext = myAesMasterContext;
    }

    public SgAesMasterContext SgAesMasterContext { get { return sgAesMasterContext; } }
    public MyAesMasterContext MyAesMasterContext { get { return myAesMasterContext; } }
    public CompanyRepository CompanyRepo { get { return new CompanyRepository(sgAesMasterContext, myAesMasterContext); } }

    public void Dispose()
    {
        sgAesMasterContext.Dispose();
        myAesMasterContext.Dispose();
    }
}

CompanyRepository.cs

public class CompanyRepository
{
    protected readonly SgAesMasterContext sgAesMasterContext;
    protected readonly MyAesMasterContext myAesMasterContext;

    public CompanyRepository(SgAesMasterContext sgAesMasterContext, MyAesMasterContext myAesMasterContext)
    {
        this.sgAesMasterContext = sgAesMasterContext;
        this.myAesMasterContext = myAesMasterContext;
    }

    public async Task<List<Company>> GetCompanies(string country)
    {
        List<Company> companies = new List<Company>();

        switch (country)
        {
            case "SG":
                companies = await sgAesMasterContext.Companies.Where(x => x.Company_Status == "A" && x.Status == "0").ToListAsync();
                break;
            case "MY":
                companies = await myAesMasterContext.Companies.Where(x => x.Company_Status == "A" && x.Status == "0").ToListAsync();
                break;
        }

        return companies;
    }
}

有什么解决方案可以使我的存储库调用动态DbContext而不使用切换用例吗？这是因为，如果我对存储库中的每个功能都使用开关盒，它将变得多余并且难以维护。

Answer 1

此解决方案适用于多租户类型的方案，在这种方案中，您具有相同的架构，需要在基于该租户的不同数据库上运行相同的查询。

您可以只有一个DbContext，但可以动态传递ConnectionString以连接到不同的数据库。

由于只有一个DbContext，因此所有存储库都将依赖于该DbContext。尽管您需要根据租户将正确的连接字符串传递给DbContext。

您可以创建并实现ITenantDbContextFactory，该请求将调查请求以识别要使用的ConnectionString并基于该字符串创建DbContext

去离子注入中的设置ITenantDbContextFactory

public class TenantDbContextFactory : ITenantDbContextFactory 
{
       public TenantDbContext GetDbContext()
       {
             string country;
               // Read Request to identify correct tenant
             switch (country)
             {
                 case "SG":
                      return new TenantDbContext("connectionstring for Sg")
                break;
                 case "MY":
                      return new TenantDbContext("connectionstring for my")
                break;
             }
       }
}

public class TenantDbContext: DbContext
{
    public DbSet<Company> Companies { get; set; }

    public TenantDbContext(DbContextOptions<TenantDbContext> options) : base(options) { }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
    }
}

public class TenantUnitOfWork: ITenantUnitOfWork
{
    private readonly TenantDbContext tenantDbContext;

    public TenantUnitOfWork(ITenantDbContextFactory tenantDbContextFactory)
    {
        this.tenantDbContext= tenantDbContextFactory.GetDbContext();
    }

    public TenantDbContext  TenantDbContext  { get { return tenantDbContext; } }
    public CompanyRepository CompanyRepo { get { return new CompanyRepository(tenantDbContext); } }

    public void Dispose()
    {
        tenantDbContext.Dispose();
    }
}

public class CompanyRepository
{
    protected readonly TenantDbContext tenantDbContext ;

    public CompanyRepository(TenantDbContext tenantDbContext)
    {
        this.tenantDbContext = tenantDbContext ;
    }

    public async Task<List<Company>> GetCompanies()
    {
        List<Company> companies = new List<Company>();

        companies = await tenantDbContext.Companies.Where(x => x.Company_Status == "A" && x.Status == "0").ToListAsync();

        return companies;
    }
}

.Net核心动态dbContext

1 个答案: