Question

我首先使用EF代码用于web api系统，但在配置中使用DbMigrator导致我的上下文导致SqlException：

ystem.Data.SqlClient.SqlException: System.Data.SqlClient.SqlException: Database 'name' already exists. Choose a different database name..

这是代码：

public Configuration()
    {
        AutomaticMigrationsEnabled = true;

        var dbMigrator = new DbMigrator(this);

        // This is required to detect changes.
        var pendingMigrationsExist = dbMigrator.GetPendingMigrations().Any();

        if (pendingMigrationsExist)
        {
            dbMigrator.Update();
        }
    }

没有调用dbMigrator.Update()，就不会执行种子方法。

如何在没有此问题的情况下运行种子方法？删除dbMigrator.Update()调用允许系统创建数据库，但不会播种任何数据。

注意：我正在使用CreateDatabaseIfNotExists初始化器，并使用上下文的构造函数设置：

public MyContext() : base("name=myconnectionstringname")
{
    Database.SetInitializer(new CreateDatabaseIfNotExists<MyContext>());
}

编辑：添加有关上下文的信息：

public class TelephonyContext : DbContext
{
    private const string Key = "ddd412345fdee012ddd41e3456789012";
    private const string Iv = "fab41e34567fk012";

    public TelephonyContext()
        : base("name=telephony-connection")
    {
        var encryptedPassword = ConfigurationManager.AppSettings["telephony-pass"];
        var password = AesEncryption.Decrypt(encryptedPassword, Key, Iv);

        Database.Connection.ConnectionString = Database.Connection.ConnectionString.Replace("XXXXXX", password);

        Database.SetInitializer(new CreateDatabaseIfNotExists<TelephonyContext>());
    }

    public virtual DbSet<SoftphoneUser> SoftphoneUserSet { get; set; }

    public virtual DbSet<InitialCall> InitialCallSet { get; set; }

    public virtual DbSet<CallAudit> CallAuditSet { get; set; }

    public virtual DbSet<RecordingErrorType> RecordingErrorTypeSet { get; set; }

    public virtual DbSet<SourceApplication> SourceApplicationSet { get; set; }

    public override int SaveChanges()
    {
        foreach (var history in ChangeTracker.Entries()
                    .Where(e => e.Entity is IModificationHistory && (e.State == EntityState.Added ||
                        e.State == EntityState.Modified))
           .Select(e => e.Entity as IModificationHistory))
        {
            history.DateModified = DateTime.Now;
            if (history.DateCreated == DateTime.MinValue)
            {
                history.DateCreated = DateTime.Now;
            }
        }

        var result = base.SaveChanges();
        foreach (var history in ChangeTracker.Entries()
                                      .Where(e => e.Entity is IModificationHistory)
                                      .Select(e => e.Entity as IModificationHistory))
        {
            history.IsDirty = false;
        }

        return result;
    }

    // todo need to sort this issue
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Maintainability", "CA1506:AvoidExcessiveClassCoupling", Justification = "TODO need to sort this issue")]
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        if (modelBuilder != null)
        {
            modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();

            modelBuilder.Configurations.Add(new SoftphoneUserConfiguration());
            modelBuilder.Configurations.Add(new InitialCallConfiguration());
            modelBuilder.Configurations.Add(new CallAuditConfiguration());

            modelBuilder.Configurations.Add(new SourceApplicationConfiguration());
            modelBuilder.Configurations.Add(new RecordingErrorTypeConfiguration());

            base.OnModelCreating(modelBuilder);
        }
    }
}

和种子方法：

protected override void Seed(TelephonyContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException(nameof(context));
        }

        Console.WriteLine("running in method Configuration.Seed()");

        var allRecordingErrorTypes = new List<RecordingErrorType>();

        foreach (RecordingErrorTypeEnumeration errorType in Enum.GetValues(typeof(RecordingErrorTypeEnumeration)))
        {
            allRecordingErrorTypes.Add(new RecordingErrorType
            {
                ErrorTypeId = errorType,
                Name = Enum.GetName(typeof(RecordingErrorTypeEnumeration), errorType),
                Description = errorType.GetDescription()
            });
        }

        context.RecordingErrorTypeSet.AddOrUpdate(allRecordingErrorTypes.ToArray());

        var a = new SourceApplication { ApplicationId = 1, ApplicationName = "TelephonyService", IsActive = true, UpdatedBy = "System" };
        var b = new SourceApplication { ApplicationId = 2, ApplicationName = "MortgagePayments", IsActive = true, UpdatedBy = "System" };
        var c = new SourceApplication { ApplicationId = 3, ApplicationName = "HomeInsurancePayments", IsActive = true, UpdatedBy = "System" };
        var d = new SourceApplication { ApplicationId = 4, ApplicationName = "CreditCardPayments", IsActive = true, UpdatedBy = "System" };

        context.SourceApplicationSet.AddOrUpdate(app =>
            new { app.ApplicationId, app.ApplicationName, app.IsActive, app.UpdatedBy }, a, b, c, d);
    }

Answer 1

我无法复制错误。这是我的代码：

public class MyContext: DbContext{
    public MyContext()
    {
        Database.SetInitializer(new CreateDatabaseIfNotExists<MyContext>());
    }

    public DbSet<Product> Products { get; set; }
}

public class Product
{
    public int ProductId { get; set; }
    public string Name { get; set; }
    public int rating { get; set; }
}

internal sealed class Configuration : DbMigrationsConfiguration<MockApplicationUser.MyContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = true;

        var dbMigrator = new DbMigrator(this);

        // This is required to detect changes.
        var pendingMigrationsExist = dbMigrator.GetPendingMigrations().Any();

        if (pendingMigrationsExist)
        {
            dbMigrator.Update();
        }
    }

    protected override void Seed(MockApplicationUser.MyContext context)
    {
        Product[] products = new Product[] { new Product { Name = "Product1", rating = 1 }, new Product { Name = "Product1", rating = 1 }, new Product { Name = "Product1", rating = 1 } };
        context.Products.AddOrUpdate(products);
    }
}

导致数据库'名称'的DbMigrator.Update已存在

1 个答案: