使用复合键更新记录 - Entity Framework Core

Question

I am having an issue updating a record with a composite key using EF Core 5 and Net Core 5. I am able to get the record using both parts of the composite key (two ids in my case) but when I save the changes to the database I get the following error:

Database operation expected to affect 1 row(s) but actually affected 24 row(s). Data may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=527962 for information on understanding and handling optimistic concurrency exceptions.

After looking in the database, it looks like entity framework is trying to update all the records in the table with same id (first part of the composite key) instead of updating the record that I got.

Has anyone else seen this behavior? Any ideas of how to get around it or what I might be doing wrong?

Here is a basic version of the table set up

Table1:

Id (PK)

Table2:

Id (PK),  
Table1Id (PK, FK)

Scenario where it fails:

Table1:

Id  
--
1  
2  

Table2:

Id, Table1Id  
------------
1, 1  
2, 1  
1, 2  
2, 2  

If I try to update the first record in Table2 (1, 1), EF would try to update it and the third record (1, 2) and throw the above error.

Code:

// Getting record    
var record = await context.Table2s
                          .FirstOrDefaultAsync(e => e.Id == 1 && e.Table1Id == 1, cancellationToken);

// Saving
await context.SaveChangesAsync(cancellationToken);

// I have also tried specifying which record to update before saving
context.Table2s.Update(record);

Configuration for Table2:

builder.ToTable("Table2");
builder.HasKey(e => new { e.Id, e.Table1Id });

builder.HasOne(e => e.Table1)
                .WithMany(m => m.Table2s)
                .HasForeignKey(e => e.Table1Id)
                .OnDelete(DeleteBehavior.Cascade);

Answer 1

It works in my own projects, I hope it will be useful.

protected override void OnModelCreating(DbModelBuilder mb) {
   mb.Entity<WebServisUser>().HasKey(x => new
   {
       x.Proje, /* Composite Keys */
       x.KulAdi /* Composite Keys */
   });
   mb.Entity<WebServisUser>().Property(e => e.Proje).IsUnicode(false);
   mb.Entity<WebServisUser>().Property(e => e.KulAdi).IsUnicode(false);
}

I have added the link other functions for better understanding.

public static class Helper
    {
        public static bool IsNull(this object value) => (value == null || Convert.IsDBNull(value) || Convert.GetTypeCode(value) == TypeCode.Empty);
        public static bool IsNotNull(this object value) => !value.IsNull();
        public static string ToPropertyName(this Expression value)
        {
            if (typeof(LambdaExpression).IsAssignableFrom(value.GetType())) { value = ((LambdaExpression)value).Body; }
            if (value is MemberExpression e_mem) { return e_mem.Member.Name; }
            else if (value is UnaryExpression e_una) { return ((MemberExpression)e_una.Operand).Member.Name; }
            else { throw new InvalidCastException(String.Format("value type can be \"{0}\" or \"{1}\"", nameof(MemberExpression), nameof(UnaryExpression))); }
        }
        public static object ChangeType(object value, Type type)
        {
            var c = TryTypeIsNullable(type, out Type _outtype);
            return (c && value.IsNull()) ? null : (_outtype.IsEnum ? Enum.ToObject(_outtype, value) : Convert.ChangeType(value, c ? Nullable.GetUnderlyingType(type) : type));
        }
        public static void SetPropertyValue<T>(this T value, string propertyname, object data) where T : class
        {
            var p = typeof(T).GetProperty(propertyname);
            p.SetValue(value, data.IsNull() ? null : ChangeType(data, p.PropertyType));
        }
        public static bool TryTypeIsNullable(Type value, out Type outvalue)
        {
            var t = (value.IsGenericType && value.GetGenericTypeDefinition().Equals(typeof(Nullable<>)));
            outvalue = (t ? value.GenericTypeArguments[0] : value); return t;
        }
        public static bool TryTypeIsAttribute<T, Y>(T value, out Y outvalue) where T : ICustomAttributeProvider where Y : Attribute
        {
            bool ret;
            try
            {
                var v = value.GetType();
                var y = typeof(Y);
                if (typeof(Assembly).IsAssignableFrom(v) && Attribute.IsDefined((Assembly)((object)value), y)) { ret = true; }
                else if (typeof(MemberInfo).IsAssignableFrom(v) && Attribute.IsDefined((MemberInfo)((object)value), y)) { ret = true; }
                else if (typeof(Module).IsAssignableFrom(v) && Attribute.IsDefined((Module)((object)value), y)) { ret = true; }
                else if (typeof(ParameterInfo).IsAssignableFrom(v) && Attribute.IsDefined((ParameterInfo)((object)value), y)) { ret = true; }
                else { ret = false; }
                outvalue = ret ? value.GetCustomAttributes(y, false).Cast<Y>().Take(1).FirstOrDefault() : default;
            }
            catch
            {
                outvalue = default;
                ret = false;
            }
            return ret;
        }
        public static void SetCompositeKey<T, TKey>(this DbContext context, T entity, Expression<Func<T, TKey>> compositekey, TKey compositekeyvalue, Action<T> actionislem = null) where T : class, new()
        {
            var t = typeof(T);
            var c = compositekey.ToPropertyName();
            var ie_prop = typeof(T).GetProperties().Where(x => x.GetMethod.IsNotNull() && x.SetMethod.IsNotNull() && !x.GetMethod.IsVirtual && !x.SetMethod.IsVirtual && !Helper.TryTypeIsAttribute(x, out NotMappedAttribute _)).Select(x => new
            {
                name = x.Name,
                iskey = x.Name == c,
                iscompositekey = Helper.TryTypeIsAttribute(x, out KeyAttribute _outkeyvalue) && _outkeyvalue.IsNotNull() && Helper.TryTypeIsAttribute(x, out DatabaseGeneratedAttribute _outdatagenvalue) && _outdatagenvalue.DatabaseGeneratedOption == DatabaseGeneratedOption.None
            });
            if (ie_prop.Where(x => x.iscompositekey).Count() < 2) { throw new KeyNotFoundException("minimum of 2 composite keys exception message..."); }
            else if (ie_prop.Any(x => x.iscompositekey && x.iskey))
            {
                var addentity = new T();
                var e = context.Entry<T>(entity);
                var dbset = context.Set<T>();
                dbset.Attach(entity);
                foreach (var item in ie_prop.Select(x => new
                {
                    x.name,
                    x.iskey
                })) { addentity.SetPropertyValue(item.name, item.iskey ? compositekeyvalue : e.Property(item.name).OriginalValue); }
                dbset.Add(addentity); /* Insert record about new key value */
                if (actionislem.IsNotNull()) { actionislem(addentity); } /* If there are other areas of connection, do the operations there with the action method. */
                dbset.Remove(entity); /* delete old value */
            }
            else { throw new Exception("compositekey must be composite key exception message..."); }
        }
    }

and example

using (var mdl = new mdlBayUniOrtak())
            {
                using (var c = new TransactionScope())
                {
                    var beforeentity = mdl.WebServisUsers.Where(x => x.Proje == "loremipsum").Take(1).FirstOrDefault();
                    var e = new Action<WebServisUser>((WebServisUser afterentity) =>
                    {
                        /* Other actions if necessary. Other foreign key operations can be done here! */
                    });
                    mdl.SetCompositeKey(beforeentity, x => x.KulAdi, "galatasaray", e);
                    mdl.SaveChanges();
                    c.Complete();
                }
            }