/// <summary>
/// Creates a function delegate that returns a <see cref="IStructuralEquatable"/> instance,
/// representing the key values for the given <paramref name="type"/>.
/// </summary>
/// <param name="type">The <see cref="Type"/> for which to build the delegate.</param>
/// <param name="dataRecord">The <see cref="IDataRecord"/> containing the target fields/columns.</param>
/// <returns>A function delegate used to retrieve key values for the given <paramref name="type"/>.</returns>
public Func <IDataRecord, IStructuralEquatable> CreateKeyDelegate(Type type, IDataRecord dataRecord)
{
IEnumerable <PropertyMappingInfo> ordinals = propertyMapper.Execute(type, dataRecord);
var keyOrdinal = GetValidPropertyMappingWithTheSmallestOrdinal(ordinals);
if (keyOrdinal == null)
{
return(null);
}
Type keyType = typeof(Tuple <>).MakeGenericType(keyOrdinal.Property.PropertyType);
var keyMethod = keyInstanceEmitter.CreateMethod(keyType);
return(dr => keyMethod(dr, new[] { keyOrdinal.Ordinal }));
}
/// <summary>
/// Executes the selector and returns the ordinals required to read the columns from the data record.
/// </summary>
/// <param name="type">The <see cref="Type"/> for which to return the ordinals.</param>
/// <param name="dataRecord">The <see cref="IDataRecord"/> that represents the available fields/columns.</param>
/// <returns>A list of ordinals.</returns>
public int[] Execute(Type type, IDataRecord dataRecord)
{
return(propertyMapper.Execute(type, dataRecord).Select(pm => pm.Ordinal).ToArray());
}
/// <summary>
/// Returns a list of <see cref="PropertyMappingInfo"/> instances that
/// represents the mapping between the fields from the <paramref name="dataRecord"/> and
/// the <paramref name="type"/> properties.
/// </summary>
/// <param name="type">The <see cref="Type"/> containing the target properties.</param>
/// <param name="dataRecord">The <see cref="IDataRecord"/> that contains the target fields/columns.</param>
/// <returns>A list of <see cref="PropertyMappingInfo"/> instances where each instance represents a match
/// between a field/column name and a property name.</returns>
public IEnumerable <PropertyMappingInfo> Execute(Type type, IDataRecord dataRecord)
{
return(cache.GetOrAdd(type, t => propertyMapper.Execute(type, dataRecord)));
}
private bool HasAtLeastOneMappedProperty(Type type, IDataRecord dataRecord)
{
return(propertyMapper.Execute(type, dataRecord).Any(pm => pm.Ordinal > -1));
}
