CODEWITHSUNDEEP
c#listlinqmerge
Ami
Ami

Reputation: 63

Condition merge while merging duplicate of two List

I have two lists, 

private List<DealResponse> L1 = new List<DealResponse>
{
    new DealResponse {detailId = "5", detailcd = "ABC", fileName = "string 1", isNgo = "0"},
    new DealResponse {detailId = "5", detailcd = "DEF", fileName = "string 2", isNgo = "0"},
    new DealResponse {detailId = "5", detailcd = "XYZ", fileName = "string ", isNgo = "0"}
};

private List<DealResponse> L2 = new List<DealResponse>
{
    new DealResponse {detailId = "5", detailcd = "ABC", fileName = "string 11", isNgo = "1"},
    new DealResponse {detailId = "6", detailcd = "MNO", fileName = "string 3", isNgo = "1"}
};

I'm trying to write a method which accepts detailId and return the result by merging above two list, and if there is duplicate (duplicate definition = when detailId, detailcd match between two lists) select entry from L2

so after merging result would be 

var Result = new List<DealResponse>
{
    new DealResponse {detailId = "5", detailcd = "ABC", fileName = "string 11", isNgo = "1"},
    new DealResponse {detailId = "5", detailcd = "DEF", fileName = "string 2", isNgo = "0"},
    new DealResponse {detailId = "5", detailcd = "XYZ", fileName = "string ", isNgo = "0"},
    new DealResponse {detailId = "6", detailcd = "MNO", fileName = "string 3", isNgo = "1"},
};

Note that in result we selected this entry from L2 since detailId = 5, detailcd = ABC was duplicate 

public List<DealResponse> GetDealResponse(string detailId)   
{
    // My main confusion is while doing union how to handle the case 
    // which I mentioned (On duplicate select entry from second list)  
    var L3 = L1.Union(L2, new DealResponseComprarer()).ToList();         
}  

public class DealResponse
{
    public string detailId { get; set; }
    public string detailcd { get; set; }
    public string fileName { get; set; }
    public string isNgo { get; set; }
}

public class DealResponseComprarer : IEqualityComparer<DealResponse>
{
    public bool Equals(DealResponse x, DealResponse y)
    {
        return x.detailId == y.detailId &&  x.detailcd == y.detailcd ;
    }

    public int GetHashCode(DealResponse obj)
    {
        return (obj.detailId.GetHashCode() + obj.detailcd.GetHashCode());
    }
}

Upvotes: 1

Views: 93

Answers (2)

Jimi
Jimi

Reputation: 32248

In case you actually want to filter your results using detailId, since this value is passed to the GetDealResponse() method, you could add a .Where condition to the equalized Union list.

public class DealResponse
{
    public string detailId { get; set; }
    public string detailcd { get; set; }
    public string fileName { get; set; }
    public string isNgo { get; set; }
}

public List<DealResponse> GetDealResponse(string detailId)
{
    return L2.Union(L1, new DealResponseComprarer())
             .Where(elm => elm.detailId.Equals(detailId)).ToList();
}


L1 = new List<DealResponse>() {
new DealResponse() { detailId = "5", detailcd = "ABC" , fileName = "string 1", isNgo = "0" },
new DealResponse() { detailId = "5", detailcd = "DEF" , fileName = "string 2", isNgo = "0" },
new DealResponse() { detailId = "5", detailcd = "XYZ" , fileName = "string ", isNgo = "0" }};

L2 = new List<DealResponse>() {
new DealResponse() { detailId = "5", detailcd = "ABC" , fileName = "string 11", isNgo = "1" },
new DealResponse() { detailId = "6", detailcd = "MNO" , fileName = "string 3", isNgo = "1" }};

string ID = "5";
List<DealResponse> L3 = GetDealResponse(ID);

Which would return this list:

{ detailId = "5", detailcd = "ABC" , fileName = "string 11", isNgo = "1" }
{ detailId = "5", detailcd = "DEF" , fileName = "string 2", isNgo = "0" }
{ detailId = "5", detailcd = "XYZ" , fileName = "string ", isNgo = "0" }

Upvotes: 2

John Wu
John Wu

Reputation: 52260

I'm trying to write a method which accepts detailId and return the result by merging above two list, and if there is duplicate (duplicate definition = when detailId, detailcd match between two lists) select entry from L2

Another way to say this is:

  1. Start with L2
  2. Add everything from L1 that isn't already in L2

This can be accomplished with one line:

var combined = L2.Concat(L1.Except(L2, new DealResponseComprarer()));

Example on DotNetFiddle

Upvotes: 1

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