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Compare two lists on one property and dont add duplicate

Hello so for some reason using various examples i havent been able to solve this.
So i have two lists one containing global values and one vlues that are set on a specific property. What i want to achieve is compare the two lists and keep the specific ones and then add the global ones that are not in the specific list based on its name.
i have tried this
var pidConfigValues = await _database.GetConfigurationValuesForPid(productGroup);
var globalConfigValues = await _database.GetGlobalConfigurationValues();
var allConfigs = pidConfigValues.Where(c => globalConfigValues.All(d => c.Name != d.Name)).ToList();
I guess something is wrong with the Where condition because the allConfigs ends up as empty. The both variables that gets compared are lists of same type of object
Example data
pidConfigValues would consist of objects like
Name: config.myConfig,
Pid: 2,
Value: 1
and globalConfigValues would be like
Name: config.myConfig,
Pid: Null,
Value: 0
Name: config.someOtherConfig,
Pid: Null,
Value: 1
So in the example above i would want allConfigs to be
Name: config.myConfig,
Pid: 2,
Value: 1
Name: config.someOtherConfig,
Pid: Null,
Value: 1
So in allConfigs only the config.myConfig with pid would be shown and from global only add the ones that does not exist in the specific one

Here is one way of doing it:
var pidConfigValues = new List<Config>()
{
new Config() { Name = "config.myConfig", Pid = 2, Value = 1}
};
var globalConfigValues = new List<Config>()
{
new Config() { Name = "config.myConfig", Pid = null, Value = 0},
new Config() { Name = "config.someOtherConfig", Pid = null, Value = 1}
};
var result = pidConfigValues.Concat(globalConfigValues)
.GroupBy(x => x.Name)
.Select(x => x.First()) //if multiple entities have the same name pick the first one which will be the one from pidConfigValues

One solution would be to use Union in combination with a custom EqualityComparer that compares the configs based on their Name-property:
// in your code:
var allConfigs = pidConfigValues.Union(globalConfigValues, new MyConfigComparer()).ToList();
// sample for the comparer:
public class MyConfigComparer : IEqualityComparer<MyConfig>
{
public bool Equals(MyConfig c1, MyConfig c2)
{
if (object.ReferenceEquals(c1, c2))
return true;
if (c1 == null || c2 == null)
return false;
return c1.Name.Equals(c2.Name, StringComparison.Ordinal);
}
public int GetHashCode(MyConfig x)
{
return x.Name.GetHashCode();
}
}

Ciao, you can use Distinct (by rewriting EqualityComparer). Here working example:
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
var pidConfigValues = new List<Configuration>();
var globalConfigValues = new List<Configuration>();
Configuration pidConfigValue = new Configuration("config.myConfig", 2, 1);
Configuration globalConfigValue1 = new Configuration("config.myConfig", null, 0);
Configuration globalConfigValue2 = new Configuration("config.someOtherConfig", null, 1);
globalConfigValues.Add(globalConfigValue1);
pidConfigValues.Add(pidConfigValue);
globalConfigValues.Add(globalConfigValue2);
List<Configuration> result = pidConfigValues.Concat(globalConfigValues)
.Distinct(new ConfigurationEqualityComparer()).ToList();
Console.WriteLine(String.Join(",", result));
Console.ReadLine();
}
}
public class Configuration
{
public string _name = "";
public Nullable<int> _pid = null;
public int _value = -1;
public Configuration(string name, Nullable<int> pid, int value)
{
this._name = name;
this._pid = pid;
this._value = value;
}
public override string ToString()
{
return "Name: " + this._name + " PID:" + this._pid + " Value:" + this._value + Environment.NewLine;
}
}
public class ConfigurationEqualityComparer
: EqualityComparer<Configuration>
{
public override bool Equals(Configuration c1, Configuration c2)
{
if (c1 == null && c2 == null)
return true;
else if (c1 == null || c2 == null)
return false;
else if (c1._name.Equals(c2._name))
{
if (c1._pid == null || c2._pid == null) return true;
else return false;
}
else
return false;
}
public override int GetHashCode(Configuration cnf)
{
int hCode = cnf._value ^ cnf._value;
return hCode.GetHashCode();
}
}
}
Explanation: Concat two lists and get only Distinct values. Equality comparer must be rewrited because we are using objects so we have to define which object is equal to another.

So your case is complicated to be solved by simple union or join operation. But simple enough to be solved by some simple select and concat operations.
What you need is to loop all loaded pidConfigValues and override a specific property with the global configuration, and then create a collection containing all unique configurations. Is that correct?
If so the solution could be like this:
var pidConfigValues = await _database.GetConfigurationValuesForPid(productGroup);
var globalConfigValues = await _database.GetGlobalConfigurationValues();
// loop through all pidConfigs and override their Pid value if matching global config exists
var allConfigs = pidConfigValues.Select(c =>
{
var matchingGlobalConfig = globalConfigValues.FirstOrDefault(g => g.Name == c.Name);
if (matchingGlobalConfig != null)
{
c.Pid = matchingGlobalConfig.Pid;
}
return c;
}).ToList();
// Find all global configs that are not matching any pidConfigValues
var productNames = pidConfigValues.Select(p => p.Name).ToArray();
var nonMatchingGlobalConfigs = globalConfigValues.Where(g => !productNames.Contains(g.Name)).ToArray();
// add non-matching global-configs to all-configs collection
allConfigs = allConfigs.Concat(nonMatchingGlobalConfigs).ToArray();

Icomparer c# List

I have a list of image name like this {"1.jpg", "10.jpg", "2.jpg"}.
I would like to sort like this {"1.jpg", "2.jpg", "10.jpg"}.
I created this comparer. That means if x or y == "DSC_10.jpg", so if list is {"DSC_1.jpg", "DSC_10.jpg", "DSC_2.jpg", ...} don't sort and keep the list.
var comparer = new CompareImageName();
imageUrls.Sort(comparer);
return imageUrls;
public class CompareImageName : IComparer<string>
{
public int Compare(string x, string y)
{
if (x == null || y == null) return 0;
var l = x.Split('/');
var l1 = y.Split('/');
int a, b;
var rs = int.TryParse(l[l.Length - 1].Split('.')[0], out a);
var rs2 = int.TryParse(l1[l1.Length - 1].Split('.')[0], out b);
if (!rs || !rs2) return 0;
if (a == b || a == 0 && b == 0) return 0;
return a > b ? 1 : -1;
}
}
This sort correctly with name {"1.jpg", "10.jpg", "2.jpg"}, but incorrectly if list is {"DSC_1.jpg", "DSC_10.jpg", "DSC_2.jpg", ...}.
I read in MSDN:
What wrong with my code?

I think you're better off doing a bit of Regex for this. Try this solution:
public class CompareImageName : IComparer<string>
{
public int Compare(string x, string y)
{
if (x == null || y == null) return 0;
var regex = new Regex(#"/(((?<prefix>\w*)_)|)((?<number>\d+))\.jpg$");
var mx = regex.Match(x);
var my = regex.Match(y);
var r = mx.Groups["prefix"].Value.CompareTo(my.Groups["prefix"].Value);
if (r == 0)
{
r = int.Parse(mx.Groups["number"].Value).CompareTo(int.Parse(my.Groups["number"].Value));
}
return r;
}
}
Apart from the Regex string itself this is easier to follow the logic.

Here is your solution check this example, following class will do the comparison
public class NumericCompare : IComparer<string>
{
public int Compare(string x, string y)
{
int input1,input2;
input1=int.Parse(x.Substring(x.IndexOf('_')+1).Split('.')[0]);
input2= int.Parse(y.Substring(y.IndexOf('_')+1).Split('.')[0]);
return Comparer<int>.Default.Compare(input1,input2);
}
}
You can make use of this class like the following:
var imageUrls = new List<string>() { "DSC_1.jpg", "DSC_10.jpg", "DSC_2.jpg" };
var comparer = new NumericCompare();
imageUrls.Sort(comparer);
Console.WriteLine(String.Join("\n",imageUrls));
Try this with simple OrderBy
var SortedList = imageUrls.OrderBy(
x=>int.Parse(
x.Substring(x.IndexOf('_')+1).Split('.')[0])
).ToList();

Basically what you want to do is sort by the numeric part within the string. You are almost there. You just have to handle the part when you split a case like this DSC_2.jpg using a . then the first part is not all digits. So you need to get digits and then compare those. Here is the code. Please note I have made the assumption you will have backslash and if that is not the case then please handle it:
public int Compare(string x, string y)
{
if (x == null || y == null) return 0;
var nameX = x.Substring(x.LastIndexOf('/'));
var nameY = y.Substring(y.LastIndexOf('/'));
var nameXParts = nameX.Split('.');
var nameYParts = nameY.Split('.');
int a, b;
var rs = int.TryParse(nameXParts[0], out a);
var rs2 = int.TryParse(nameYParts[0], out b);
var nameXDigits = string.Empty;
if (!rs)
{
for (int i = 0; i < nameXParts[0].Length; i++)
{
if (Char.IsDigit(nameXParts[0][i]))
nameXDigits += nameXParts[0][i];
}
}
var nameYDigits = string.Empty;
if (!rs2)
{
for (int i = 0; i < nameYParts[0].Length; i++)
{
if (Char.IsDigit(nameYParts[0][i]))
nameYDigits += nameYParts[0][i];
}
}
int.TryParse(nameXDigits, out a);
int.TryParse(nameYDigits, out b);
if (a == b || a == 0 && b == 0) return 0;
return a > b ? 1 : -1;
}

Don't use imageUrls.Sort(comparer); on List because it doesn't accept 0 value as keeping the order of elements.
Reason:
The Sort performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.
Link: https://msdn.microsoft.com/en-gb/library/w56d4y5z.aspx
Solution: Let's try to use OrderBy with your compare
var imageUrls1 = new List<string>() { "1.jpg", "10.jpg", "2.jpg" };
var imageUrls2 = new List<string>() { "DSC_1.jpg", "DSC_10.jpg", "DSC_2.jpg" };
var comparer = new CompareImageName();
//Sort normally
imageUrls1 = imageUrls1.OrderBy(p=>p, comparer).ToList();
//Keep the order as your expectation
imageUrls2 = imageUrls2.OrderBy(p=>p, comparer).ToList();

Maybe you can try doing this in a function instead of writing a comparator. I can't think of a good way to implement this logic as a comparator since there are different rules based on the contents (don't sort if the file name is not numeric).
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
namespace sortinglists
{
public class MainProgram
{
public static void Main()
{
var imageUrlsNumbers = new List<string>();
imageUrlsNumbers.Add("c:/a/b/1.jpg");
imageUrlsNumbers.Add("c:/a/b/10.jpg");
imageUrlsNumbers.Add("c:/a/b/2.jpg");
CustomSort(ref imageUrlsNumbers);
foreach (var imageUrl in imageUrlsNumbers)
{
Console.WriteLine(imageUrl);
}
var imageUrlsText = new List<string>();
imageUrlsText.Add("c:/a/b/DSC_1.jpg");
imageUrlsText.Add("c:/a/b/DSC_10.jpg");
imageUrlsText.Add("c:/a/b/DSC_2.jpg");
CustomSort(ref imageUrlsText);
foreach (var imageUrl in imageUrlsText)
{
Console.WriteLine(imageUrl);
}
}
public static void CustomSort(ref List<string> imageUrls)
{
if (imageUrls
.Select(s => s.Substring(s.LastIndexOf("/", StringComparison.OrdinalIgnoreCase) + 1))
.Select(t => t.Substring(0, t.IndexOf(".", StringComparison.OrdinalIgnoreCase)))
.Where(u => new Regex("[A-Za-z_]").Match(u).Success)
.Any())
{
imageUrls = imageUrls
.Select(x => x.Substring(x.LastIndexOf("/", StringComparison.OrdinalIgnoreCase) + 1))
.ToList();
}
else
{
imageUrls = imageUrls
.Select(v => v.Substring(v.LastIndexOf("/", StringComparison.OrdinalIgnoreCase) + 1))
.OrderBy(w => Convert.ToInt32(w.Substring(0, w.LastIndexOf(".", StringComparison.OrdinalIgnoreCase))))
.ToList();
}
}
}
}
The output for imageUrlsNumbers after sorting is:
1.jpg
2.jpg
10.jpg
And the output for imageUrlsText after sorting is:
DSC_1.jpg
DSC_10.jpg
DSC_2.jpg

How to dynamically GroupBy using Linq

There are several similar sounding posts, but none that do exactly what I want.
Okay, so imagine that I have the following data structure (simplified for this LinqPad example)
public class Row
{
public List<string> Columns { get; set; }
}
public List<Row> Data
=> new List<Row>
{
new Row { Columns = new List<string>{ "A","C","Field3"}},
new Row { Columns = new List<string>{ "A","D","Field3"}},
new Row { Columns = new List<string>{ "A","C","Field3"}},
new Row { Columns = new List<string>{ "B","D","Field3"}},
new Row { Columns = new List<string>{ "B","C","Field3"}},
new Row { Columns = new List<string>{ "B","D","Field3"}},
};
For the property "Data", the user will tell me which column ordinals to GroupBy; they may say "don't group by anything", or they may say "group by Column[1]" or "group by Column[0] and Column[1]".
If I want to group by a single column, I can use:
var groups = Data.GroupBy(d => d.Columns[i]);
And if I want to group by 2 columns, I can use:
var groups = Data.GroupBy(d => new { A = d.Columns[i1], B = d.Columns[i2] });
However, the number of columns is variable (zero -> many); Data could contain hundreds of columns and the user may want to GroupBy dozens of columns.
So the question is, how can I create this GroupBy at runtime (dynamically)?
Thanks
Griff

With that Row data structure what are you asking for is relatively easy.
Start by implementing a custom IEqualityComparer<IEnumerable<string>>:
public class ColumnEqualityComparer : EqualityComparer<IEnumerable<string>>
{
public static readonly ColumnEqualityComparer Instance = new ColumnEqualityComparer();
private ColumnEqualityComparer() { }
public override int GetHashCode(IEnumerable<string> obj)
{
if (obj == null) return 0;
// You can implement better hash function
int hashCode = 0;
foreach (var item in obj)
hashCode ^= item != null ? item.GetHashCode() : 0;
return hashCode;
}
public override bool Equals(IEnumerable<string> x, IEnumerable<string> y)
{
if (x == y) return true;
if (x == null || y == null) return false;
return x.SequenceEqual(y);
}
}
Now you can have a method like this:
public IEnumerable<IGrouping<IEnumerable<string>, Row>> GroupData(IEnumerable<int> columnIndexes = null)
{
if (columnIndexes == null) columnIndexes = Enumerable.Empty<int>();
return Data.GroupBy(r => columnIndexes.Select(c => r.Columns[c]), ColumnEqualityComparer.Instance);
}
Note the grouping Key type is IEnumerable<string> and contains the selected row values specified by the columnIndexes parameter, that's why we needed a custom equality comparer (otherwise they will be compared by reference, which doesn't produce the required behavior).
For instance, to group by columns 0 and 2 you could use something like this:
var result = GroupData(new [] { 0, 2 });
Passing null or empty columnIndexes will effectively produce single group, i.e. no grouping.

you can use a Recursive function for create dynamic lambdaExpression. but you must define columns HardCode in the function.

Remove duplicate rows from two dimensional list

I have a two-dimensional list of strings (List<List<string>>).
Is there an easy way to remove the duplicate rows? That is the List<string> that are equal.

Build a custom IEqualityComparer based on SequenceEqual :
class ListComparer : IEqualityComparer<List<string>>
{
public bool Equals(List<string> x, List<string> y)
{
if (x == y)
return true ;
if (x == null || y == null)
return false ;
// Order if you need
return x.SequenceEqual(y) ;
}
public int GetHashCode(List<string> obj)
{
if (obj == null)
return 0;
unchecked
{
return obj.Select(e => e.GetHashCode()).Aggregate(17, (a, b) => 23 * a + b);
}
}
}
Apply Distinct() with the comparer :
List<List<string>> original = ...
var sortedListOfList = original.Distinct(new ListComparer()).ToList() ;

You did not specify if the lists should be compared with or without ordering.
Without ordering it should be:
List<List<string>> source = *yourLists*;
var sortedList = source.Distinct();

Compare Two Liste <T>

how can i compare 2 list ?
public class Pers_Ordre : IEqualityComparer<Pers_Ordre>
{
int _ordreId;
public int LettreVoidID
{
get { return _LettreVoidID; }
set { _LettreVoidID = value; }
}
string _OrdreCummul;
public string OrdreCummul
{
get { return _OrdreCummul; }
set { _OrdreCummul = value; }
}
// Products are equal if their names and product numbers are equal.
public bool Equals(Pers_Ordre x, Pers_Ordre y)
{
//Check whether the compared objects reference the same data.
if (Object.ReferenceEquals(x, y)) return true;
//Check whether any of the compared objects is null.
if (Object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null))
return false;
//Check whether the products' properties are equal.
return x.LettreVoidID == y.LettreVoidID && x.OrdreCummul == y.OrdreCummul;
}
// If Equals() returns true for a pair of objects
// then GetHashCode() must return the same value for these objects.
public int GetHashCode(Pers_Ordre product)
{
//Check whether the object is null
if (Object.ReferenceEquals(product, null)) return 0;
//Get hash code for the Name field if it is not null.
int hashProductName = product.OrdreCummul == null ? 0 : product.OrdreCummul.GetHashCode();
//Get hash code for the Code field.
int hashProductCode = product.LettreVoidID.GetHashCode();
//Calculate the hash code for the product.
return hashProductName ^ hashProductCode;
}
}
and i compare like this:
private void simpleButton_Comparer_Click(object sender, EventArgs e)
{
string LeFile_Client = System.IO.Path.Combine(appDir, #"FA.csv");
string LeFile_Server = System.IO.Path.Combine(appDir, #"FA_Server.csv");
List<Pers_Ordre> oListClient = Outils.GetCsv(LeFile_Client).OrderBy(t => t.LettreVoidID).ToList();
List<Pers_Ordre> oListServert = Outils.GetCsvServer(LeFile_Server).OrderBy(t => t.LettreVoidID).ToList();
List<Pers_Ordre> LeDiff = new List<Pers_Ordre>();
LeDiff = oListServert.Except(oListClient).ToList();
string Noid = "", OdreID = "";
foreach (var oDiff in LeDiff)
{
Noid += oDiff.LettreVoidID + " ";
OdreID += oDiff.OrdreCummul + " ";
}
MessageBox.Show(Noid + "--" + OdreID);
}
i can not get the right result.
The Lists contain class objects and we would like to iterate through one list, looking for the same item in a second List and report any differences.
to get object that contains in List A but not in List B
and vice versa.

Your current .Except() call will find items from Server that are missing on the client, but it will not find items on the client that are missing on the server.
Try this:
private void simpleButton_Comparer_Click(object sender, EventArgs e)
{
string LeFile_Client = System.IO.Path.Combine(appDir, #"FA.csv");
string LeFile_Server = System.IO.Path.Combine(appDir, #"FA_Server.csv");
var ListClient = Outils.GetCsv(LeFile_Client).OrderBy(t => t.LettreVoidID);
var ListServer = Outils.GetCsvServer(LeFile_Server).OrderBy(t => t.LettreVoidID);
var LeDiff = ListServer.Except(ListClient).Concat(ListClient.Except(ListServer));
var result = new StringBuilder();
foreach (var Diff in LeDiff)
{
result.AppendFormat("{0} --{1} ", Diff.LettreVoidID, Diff.OrdreCummul);
}
MessageBox.Show(Noid.ToString() + "--" + OdreID);
}
This code should also be significantly faster than your original, as it avoids loading the results into memory until it builds the final string. This code in performs the equivalent of two separate sql LEFT JOINs. We could make it faster still by doing one FULL JOIN, but that would require writing our own linq operator method as well.