Question

我在两个实体之间有多对多的关系。一切正常。有没有办法在中间表中定义FK的名称（StoresPushNotifications）？

要问的原因是mysql不允许定义长约束名称。它会生成随机FK。当我尝试将迁移设置为较早的步骤时，它会中断迁移。

[Table("Stores")]
public class StoreEntity
{
    [Key]
    public int Id { get; set; }

    public virtual ICollection<PushNotificationEntity> PushNotifications { get; set; }
}


[Table("PushNotifications")]
public class PushNotificationEntity
{
    [Key]
    public int Id { get; set; }
    public ICollection<StoreEntity> Stores { get; set; }
}

在我的上下文文件中，

modelBuilder.Entity<StoreEntity>()
    .HasMany<PushNotificationEntity>(s => s.PushNotifications)
    .WithMany(c => c.Stores)                
    .Map(cs =>
    {
        cs.MapLeftKey("StoreId");
        cs.MapRightKey("PushNotificationId");
        cs.ToTable("StoresPushNotifications");
    });

Answer 1

我遇到了类似的问题，实际上它与迁移密钥的长度相关，而不是外键。

我通过将迁移配置方法修改为：

来解决

internal sealed class Configuration : DbMigrationsConfiguration<CCDatabase.CCDbContext>

public Configuration()
{
    AutomaticMigrationsEnabled = false;
    MigrationsDirectory = @"Migrations";

    SetSqlGenerator("MySql.Data.MySqlClient", new MySql.Data.Entity.MySqlMigrationSqlGenerator());

    SetHistoryContextFactory("MySql.Data.MySqlClient", (conn, schema) => new MySqlHistoryContext(conn, schema));
}

然后添加此方法以限制密钥长度

public class MySqlHistoryContext : HistoryContext
{

    public MySqlHistoryContext(DbConnection connection, string defaultSchema) : base(connection, defaultSchema)
    {

    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        modelBuilder.Entity<HistoryRow>().Property(h => h.MigrationId).HasMaxLength(100).IsRequired();
        modelBuilder.Entity<HistoryRow>().Property(h => h.ContextKey).HasMaxLength(200).IsRequired();
    }
}

以多对多关系定义FK名称

1 个答案: