Hi folks,
I am wondering how to use sqlite's manifest typing capabilities with nhibernate?
Put simply, suppose I have a class:
Code:
class A
{
public virtual object SomeValue { get; set; }
}
the type of SomeValue is basically in the set of .NET IConvertible types (primitives like bool, byte, char, int16, double, float etc.), plus byte[].
I am trying to create a nhibernate mapping for A to reflect this - so that I can basically set SomeValue to an arbitrary value and retrieve it later on as that value. It does not atter if the type is not exactly preserved as long as the value is preserved (ie I could set SomeValue = someUInt16Value, and when persisted and retrieved later it is ok to obtain a SomeValue of another type, provided it can be cast back to the original).
So far I have tried Creating an implementation of IUserType to try and handle this. However I don't know what to return for the SqlType[] SqlTypes. I considered new SqlType(DbType.Object) but when I try to generate a schema from this I get a
System.ArgumentException: Dialect does not support DbType.ObjectIf I try another data type then I get various cast exceptions when trying to convert the type. For instance if i use a DbType.Binary, and set someValue to an int32, upon attempting to commit I get
System.InvalidCastException: Unable to cast object of type 'System.Int32' to type 'System.Byte[]'.How can I achieve this?
Attached code below for implementation of IUserType (based on
http://intellect.dk/post/Implementing-c ... rnate.aspx )
Code:
public class DataElementType : IUserType
{
SqlType baseType = new SqlType(DbType.Binary);
public SqlType[] SqlTypes
{
get
{
return new[] { baseType };
}
}
public System.Type ReturnedType
{
get { return typeof(object); }
}
public new bool Equals(object x, object y)
{
if (x == null)
return false;
else
return x.Equals(y);
}
public int GetHashCode(object x)
{
return x.GetHashCode();
}
public object NullSafeGet(IDataReader rs, string[] names, object owner)
{
return rs[names[0]];
}
public void NullSafeSet(IDbCommand cmd, object value, int index)
{
var param = new SQLiteParameter(baseType.DbType, value);
cmd.Parameters.Insert(index, param);
}
public object DeepCopy(object value)
{
if (value == null) return null;
return value;
}
public bool IsMutable
{
get { return false; }
}
public object Replace(object original, object target, object owner)
{
return original;
}
public object Assemble(object cached, object owner)
{
return cached;
}
public object Disassemble(object value)
{
return value;
}
}
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