how to combined "collectionResult" based on DataType

Question

I have below class structure,

 public class CollectionProperty
{
    public string Name { get; set; }

    public object Value { get; set; }
    public string DataType { get; set; }
}

public class Instance
{
    public string Name { get; set; }
    public List<CollectionProperty> CollectionProperties { get; set; }
}

public class CollectionResult
{
    public string Asset { get; set; }
    public List<Instance> Instances { get; set; }
}

I have below collection result with 2 instance having various collection property with 2 data types double and string.

var collectionResult = new CollectionResult
        {
            Asset = "A1",
            Instances = new List<Instance>
            {
                new Instance
                {
                    Name = "Instance-1",
                    CollectionProperties = new List<CollectionProperty>
                    {
                        new CollectionProperty {Name = "N1", Value = 10, DataType = "Double"},
                        new CollectionProperty {Name = "N2", Value = "S1", DataType = "String"}
                    }
                },
                new Instance
                {
                    Name = "Instance-2",
                    CollectionProperties = new List<CollectionProperty>
                    {
                        new CollectionProperty {Name = "N1", Value = 20, DataType = "Double"},
                        new CollectionProperty {Name = "N2", Value = "S2", DataType = "String"}
                    }
                }
            }
        };

Now my goal to split the collection result various instance and group them based on data type. With below code I am able to split put but it's giving me 4 collection results, but it's should give 2 (2 for double and 2 for string), please suggest. Thanks!

var X = collectionResult.Instances
            .SelectMany(collectionInstance => collectionInstance.CollectionProperties,
                (collectionInstance, collectionProperty) =>
                    new
                    {
                        CollectionResult = new CollectionResult
                        {
                            Asset = collectionResult.Asset,
                            Instances = new List<Instance>
                            {
                                new Instance
                                {
                                    Name = collectionInstance.Name,
                                    CollectionProperties = new List<CollectionProperty>
                                    {
                                        collectionProperty
                                    }
                                }
                            },
                        },
                        Instance = collectionInstance.Name,
                        Property = collectionProperty.Name,
                        DataType = collectionProperty.DataType
                    });

Answer 1

You just need to simply add a GroupBy statement after your selectMany:

var X = collectionResult.Instances
        .SelectMany(collectionInstance => collectionInstance.CollectionProperties,
            (collectionInstance, collectionProperty) =>
                new
                {
                    CollectionResult = new CollectionResult
                    {
                        Asset = collectionResult.Asset,
                        Instances = new List<Instance>
                        {
                            new Instance
                            {
                                Name = collectionInstance.Name,
                                CollectionProperties = new List<CollectionProperty>
                                {
                                    collectionProperty
                                }
                            }
                        },
                    },
                    Instance = collectionInstance.Name,
                    Property = collectionProperty.Name,
                    DataType = collectionProperty.DataType
                }).GroupBy(c => c.DataType);

In this way you will have two groups, which have been grouped with double and string keys: