c# – 以多对多关系定义FK名称

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(StoresPushNotifications)中定义FK的名称？

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Context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");
    });

解决方法:

我有一个类似的问题,它实际上与迁移密钥长度相关而不是外键.

我通过将迁移配置方法修改为：

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();
    }
}   

标签：c,mysql,entity-framework,ef-code-first,code-first
来源： https://codeday.me/bug/20190710/1428960.html