如何使用非主键在两个实体之间创建关系？

Question

我有这两类账户和支付。

public class Account
{
   public int Id { get; set; }
   public string BankName { get; set; }
   public string AccountNumber { get; set; }
   public string Currency { get; set; }
   public string ExternalAccountId { get; set; }
   .
   .
}
public class Payout
{
   public int Id { get; set; }
   public string Status { get; set; }
   public decimal Amount { get; set; }
   public DateTime ArrivalDate { get; set; }
   public string BalanceTransactionId { get; set; }
   public int UserId { get; set; }
   public User User { get; set; }
   .
   .
}

当我收到并创建一个新的“付款”实体时，“BalanceTransactionId”与帐户中的“ExternalAccountId”相同。

当我获取用户“支出”时，我想查询并从“帐户”中获取一些值

例如

var payouts = await _dbContext.Payouts.where(p => p.UserId == id)
    .Select(p => new {
        Amount = p.Amount,
        ArrivalDate = p.ArrivalDate,
        BankName = p.Account.BankName,
        AccountNumber = p.Account.AccountNumber
 }).ToListAsync()

问题 - 如何使用流畅的 API 在“BalanceTransactionId”和“ExternalAccountId”之间创建这种关系，它在类中会是什么样子？

更新 - 我添加了这个但不确定它是否正确

记账

public ICollection<Payout> Payouts { get; set; }

付款

public string BalanceTransactionId { get; set; }
public Account Account { get; set; }

到数据上下文

modelBuilder.Entity<Account>()
    .HasMany(t => t.Payouts)
    .WithOne(g => g.Account)
    .HasForeignKey(g => g.BalanceTransactionId)
    .OnDelete(DeleteBehavior.Restrict);
   

Answer 1

你可以这样配置它：

protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Payout>()
            .HasOne<Account>()
            .WithMany<Payout>()
            .HasForeignKey<Payout>(p => p.BalanceTransactionId)
            .HasPrincipalKey(b => b.ExternalAccountId);
    }

要查询值，您可以使用以下语法：

var payouts = await _dbContext.Payouts.where(p => p.UserId == id)
    .Select(p => new {
        Amount = p.Amount,
        ArrivalDate = p.ArrivalDate,
        BankName = _dbcontext.Accounts.Single(a => p.BalanceTransactionId == a.ExternalAccountId).BankName,
        AccountNumber = _dbcontext.Accounts.Single(a => p.BalanceTransactionId == a.ExternalAccountId).AccountNumber
 }).ToListAsync()