EFCore-在SqlServerLocalDb中創建意外的不完整行

我使用了 VS2022 中的 EFCore Power Tools，并將它創建的圖表與我的預期架構進行了比較——它們匹配！

這是資料庫背景關系 C#：

public class BillByTimeContext : DbContext
    {
        public BillByTimeContext(DbContextOptions<BillByTimeContext> options) : base(options)
        {
            RelationalDatabaseCreator databaseCreator =
                        (RelationalDatabaseCreator)this.Database.GetService<IDatabaseCreator>();
            databaseCreator.EnsureCreated();
        }

        public DbSet<ClientOrg>? ClientOrg { get; set; }
        public DbSet<Contract>? Contract { get; set; }
        public DbSet<PurchaseOrder>? PurchaseOrder { get; set; }
        public DbSet<Tenant> Tenant { get; set; }
        public DbSet<TenantManager>? TenantManager { get; set; }
        public DbSet<Timesheet>? Timesheet { get; set; }
        public DbSet<TimesheetHistory>? TimesheetHistory { get; set; }
        public DbSet<Worker>? Worker { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Tenant>()
                .HasIndex(x => x.Name)
                .IsUnique();

            modelBuilder.Entity<TenantManager>()
                .HasIndex(x => x.Email)
                .IsUnique();

            modelBuilder.Entity<Worker>()
                .HasMany(p => p.Contracts)
                .WithOne(t => t.Worker)
                .OnDelete(DeleteBehavior.NoAction);

            modelBuilder.Entity<Timesheet>()
                .HasMany(p => p.TimesheetHistories)
                .WithOne(t => t.Timesheet)
                .OnDelete(DeleteBehavior.NoAction);

            modelBuilder.Entity<Worker>()
                .HasMany(p => p.TimesheetHistories)
                .WithOne(t => t.Worker)
                .OnDelete(DeleteBehavior.NoAction);

            modelBuilder.Entity<Contract>()
                .Property(x => x.UnitCharge)
                .HasPrecision(10, 2);

            modelBuilder.Entity<PurchaseOrder>()
                .Property(x => x.Amount)
                .HasPrecision(10, 2);

            modelBuilder.Entity<Timesheet>()
                .Property(x => x.Monday)
                .HasPrecision(10, 2);
            modelBuilder.Entity<Timesheet>()
                .Property(x => x.Tuesday)
                .HasPrecision(10, 2);
            modelBuilder.Entity<Timesheet>()
                .Property(x => x.Wednesday)
                .HasPrecision(10, 2);
            modelBuilder.Entity<Timesheet>()
                .Property(x => x.Thursday)
                .HasPrecision(10, 2);
            modelBuilder.Entity<Timesheet>()
                .Property(x => x.Friday)
                .HasPrecision(10, 2);
            modelBuilder.Entity<Timesheet>()
                .Property(x => x.Saturday)
                .HasPrecision(10, 2);
            modelBuilder.Entity<Timesheet>()
                .Property(x => x.Sunday)
                .HasPrecision(10, 2);
        }

    }

我有一個呼叫以下SeedData方法的xunit測驗：

public static void SeedData(BillByTimeContext context)
        {

            context.Database.EnsureCreated();

            var timesheetHistory = new TimesheetHistory
            {
                Timestamp = new DateTime(2022, 1, 7, 14, 30, 0),
                StatusId = TimesheetStatus.PendingApproval
            };

            var timesheet = new Timesheet
            {
                Monday = 1,
                Tuesday = .5M,
                Wednesday = 1,
                Thursday = 0,
                Friday = 1,
                WeekCommencingMonday = new DateTime(2022, 01, 03),
                TimesheetHistories = new List<TimesheetHistory> { timesheetHistory },
            };

            var purchaseOrder = new PurchaseOrder
            {
                DateIssued = DateTime.Now,
                Amount = 5462.5M,
                Timesheets = new List<Timesheet> { timesheet }
            };

            var clientManager = new ClientManager
            {
                FirstName = "Paul",
                LastName = "Arndel",
                Email = "[email protected]",
                SmsNumber = "867428764",
                TimesheetHistories = new List<TimesheetHistory> { timesheetHistory }
            };

            var contract = new Contract
            {
                UnitId = ContractUnits.Days,
                UnitCharge = 550,
                Timesheets = new List<Timesheet> { timesheet }
            };

            var clientOrg = new ClientOrg
            {
                Name = "BRC",
                PurchaseOrders = new List<PurchaseOrder> { purchaseOrder },
                ClientManagers = new List<ClientManager> { clientManager },
                Contracts = new List<Contract> { contract },
                Timesheets = new List<Timesheet> { timesheet }
            };

            var tenantManager = new TenantManager
            {
                FirstName = "Rob",
                LastName = "Bowman",
                Email = "[email protected]",
                ClientOrgs = new List<ClientOrg> { clientOrg }
            };

            var worker = new Worker
            {
                FirstName = "Fabio",
                LastName = "Capello",
                Email = "[email protected]",
                Contracts = new List<Contract> { contract },
                TimesheetHistories= new List<TimesheetHistory> { timesheetHistory }
            };

            var tenant = context.Tenant.FirstOrDefault(x => x.Name == "BizTalkers");
            if (tenant == null)
            {
                context.Tenant.Add(new Tenant
                {
                    Name = "BizTalkers",
                    TenantManagers = new List<TenantManager> { tenantManager },
                    Workers = new List<Worker> { worker }
                }); ;
            }

            context.SaveChanges();

如果我清除資料庫中的所有資料并運行測驗，則會出現以下錯誤：

---- Microsoft.Data.SqlClient.SqlException : Cannot insert duplicate key row in object 'dbo.Tenant' with unique index 'IX_Tenant_Name'. The duplicate key value is ()

誰能告訴我為什么它試圖在“租戶”表中創建多個記錄？

uj5u.com熱心網友回復：

哦.. 剛剛注意到你在 github 上鏈接了你的整個專案——這很有用并證實了我的懷疑：

//worker class
public Tenant Tenant { get; set; } = new();


//tenantmanager class
public Tenant Tenant { get; set; } = new();

每次您創建一個新工人時，它都會創建一個新租戶。EF 會將此視為必須保存的物件。您的圖表至少包含 1 個作業人員（1 個租戶名稱為空白）和 1 個租戶經理（1 個租戶名稱為空白），因此看起來像

{Tenant "BizTalkers"} --has-some--> [ {Worker "Fabio"} --has-one--> { Tenant "" } ]
           \
            `--has-some--> [ {TenantManager "Rob"} --has-one--> { Tenant "" } ]

目前我不知道為什么 EFCPT 會以這種方式生成物體（如果它確實生成了？）——我的不知道。我不確定它是您打開的選項，還是資料庫端某些東西的結果..如果我發現了什么，我會更新答案，但現在我相信你的問題是由這。= new()從這些道具中洗掉，或在初始化程式中將它們設定為 null，或以其他方式構建圖形（將您創建的租戶設定為您創建的 Worker 的租戶，覆寫new() Tenant它擁有的，而不是設定您創建的 Worker成為您創建的租戶的工人之一）

另外，腳注，通常我會說“避免大規模替換子物體的整個串列” - 這些集合通常new在建構式/類道具初始化程式中作為空 HashSets 出于某種原因，您只需添加到它們而不是替換它們。如果您替換它們，更改跟蹤器可能會認為您正在洗掉內容，并且會發生各種瘋狂的事情

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