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Delete a record by matching Value

I have a dictionary where values are stored in the following format -
userID, empDetails
For example,
1234, 'empName,jobDesc,CardNumber,Type'
I have to compare this information with another set of information such that -
If entered userId is present in the above dictionary, then remove this record from the dictionary.
If entered CardNumber is present (here userId is not known) in the above dictionary, then remove this record from the dictionary.
The first condition is simple and can be done by
dictionary.Remove(key)
But I am confused as to how would I implement the second condition. I want something like
if(CardNumber.PresentinAboveDictionary)
then
Remove that record
I know we can compare a partial string in a key like this, but I want to remove the record.
Check if any part of a hashtable value contains certain string c#

Assuming the employment details in your dictionary are a string in the specified format you would need to:
Search the values within the dictionary
Parse/Split the values to get the card numbers
Check the card numbers to see if they match the card number you are checking
Return the key value pair when a match occurs
Remove the entry for the key in the returned key value pair
Example code for the solution:
var dictionary = new Dictionary<int, string>() { { 1, "empName,jobDesc,124124134,Type" } };
var cardNumber = 124124134;
var entry = dictionary.FirstOrDefault(x => DoEmploymentDetailsContainCardNumber(x.Value, cardNumber));
if (!entry.Equals(default(KeyValuePair<int, string>)))
{
dictionary.Remove(entry.Key);
}
Method that checks if card number is present in employment details:
private static bool DoEmploymentDetailsContainCardNumber(string empDetails, int cardNumber)
{
var splitEmpDetails = empDetails.Split(',');
var empDetailsCardNumber = splitEmpDetails[2];
return empDetailsCardNumber == cardNumber.ToString();
}

Instead of Dictionary you can use a strongly typed List
Use the Linq builtin Remove method
Use Parallel.ForEach, iterate the list and remove the item (beware, takes more time)
pseudo code:
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Linq;
using System.Collections;
namespace ConsoleApp4
{
public class Employee
{
public Employee(int userID, string empDetails)
{
string[] props = empDetails.Split(new char[] { ',' }, StringSplitOptions.None);
this.userID = userID;
this.empName = props[0];
this.jobDesc = props[1];
this.CardNumber = props[2];
this.Type = props[3];
}
public int userID { get; set; }
public string empName { get; set; }
public string jobDesc { get; set; }
public string CardNumber { get; set; }
public string Type { get; set; }
}
public class MyCustomList : List<Employee>
{
public void Add(int userID, string empDetails)
{
this.Add(new Employee(userID, empDetails));
}
public bool Remove(string CardNumber)
{
bool found = false ;
Parallel.ForEach(this,
(i, state) =>
{
if (i.CardNumber == CardNumber)
{
this.Remove(i);
state.Break();
}
});
return found;
}
public bool RemoveV2(string CardNumber)
{
bool found = false;
if (this.Any(x => x.CardNumber == CardNumber))
{
this.Remove(this.Where(x => x.CardNumber == CardNumber).First());
found = true;
}
return found;
}
}
class Program
{
static void Main(string[] args)
{
var dict = new MyCustomList();//userID, empDetails list
dict.Add(12341, "empName1,jobDesc,CardNumber1,Type");
dict.Add(12342, "empName2,jobDesc,CardNumber2,Type");
dict.Add(12343, "empName3,jobDesc,CardNumber3,Type");
dict.Add(12344, "empName4,jobDesc,CardNumber4,Type");
dict.Add(12345, "empName5,jobDesc,CardNumber5,Type");
dict.Add(12346, "empName6,jobDesc,CardNumber6,Type");
dict.Add(12347, "empName7,jobDesc,CardNumber7,Type");
dict.Add(12348, "empName8,jobDesc,CardNumber8,Type");
//remove CardNumber5
dict.Remove("CardNumber5");
Console.Write(dict);
}
}
}

you can follow the simple approach to remove the key by using a loop here.
Here I am assuming that there is no key with a value of -1 in the dictionary.
int keyToRemove = -1;
foreach (var entry in dictionary)
{
if (entry.Value.Contains(CardNumber))
{
keyToRemove = entry.Key;
break;
}
}
if (keyToRemove != -1)
{
dictionary.Remove(keyToRemove);
}

This is possibly overkill and is not optimised for reading the full dataset repeatedly but it is considerably faster than the accepted solution. I put together a test of the solution below which did the following:
Generated 1,000,000 data rows with unique IDs and card numbers (the solution would also work if the card numbers were not unique)
Randomly removed 100,000 data items by ID and 100,000 data items by card number
Generated a list of the remaining data items
The process took around 75 seconds.
I then tried to repeat steps 1) and 2) using the accepted answer - after around 10 minutes it's about 7% of the way through removing data items. Therefore I think the solution below is around 2 orders of magnitude faster for this type of operation.
There are probably better doubley linked list implementations out there but I am not too familiar with any of them.
namespace Question
{
public class EmployeeCollection
{
private readonly Dictionary<int, ListNode<EmployeeDetails>> _idDictionary = new();
private readonly Dictionary<string, Dictionary<int, EmployeeDetails>> _cardNumberDictionary = new();
private readonly LinkedList<EmployeeDetails> _list = new();
public void AddEmployee(EmployeeDetails details)
{
var node = new ListNode<EmployeeDetails>(details);
_list.AddToStart(node);
_idDictionary.Add(details.Id, node);
if(!_cardNumberDictionary.ContainsKey(details.CardNumber))
{
_cardNumberDictionary.Add(details.CardNumber, new Dictionary<int, EmployeeDetails>());
}
_cardNumberDictionary[details.CardNumber].Add(details.Id, details);
}
public void RemoveById(int id)
{
if (_idDictionary.TryGetValue(id, out var node))
{
_idDictionary.Remove(id);
_list.Remove(node);
var list = _cardNumberDictionary[node.Value.CardNumber];
list.Remove(id);
if(list.Count == 0)
{
_cardNumberDictionary.Remove(node.Value.CardNumber);
}
}
}
public void RemoveByCardNumber(string cardNumber)
{
if (_cardNumberDictionary.TryGetValue(cardNumber, out var employees))
{
_cardNumberDictionary.Remove(cardNumber);
foreach (var employee in employees)
{
if (_idDictionary.TryGetValue(employee.Key, out var node))
{
_list.Remove(node);
}
}
}
}
public IEnumerable<EmployeeDetails> Employees => _list.GetAllValues();
public EmployeeDetails? GetById(int id)
{
if(_idDictionary.ContainsKey(id))
{
return _idDictionary[id].Value;
}
return null;
}
}
public class EmployeeDetails
{
public int Id { get; init; }
public string Name { get; init; }
public string JobDescription { get; init; }
public string CardNumber { get; init; }
public string Type { get; init; }
public static EmployeeDetails FromData(int id, string details)
{
var parts = details.Split(',');
return new EmployeeDetails
{
Id = id,
Name = parts[0],
JobDescription = parts[1],
CardNumber = parts[2],
Type = parts[3],
};
}
}
public class LinkedList<T>
{
public int Count { get; private set; }
private ListNode<T>? Start { get; set; }
private ListNode<T>? End { get; set; }
public bool IsEmpty => Count == 0;
public void AddToStart(ListNode<T> node)
{
ArgumentNullException.ThrowIfNull(nameof(node));
node.Next = null;
node.Previous = null;
if (IsEmpty)
{
Start = End = node;
}
else
{
Start!.Previous = node;
node.Next = Start;
Start = node;
}
Count++;
}
public void Remove(ListNode<T> node)
{
if (node != Start)
{
node.Previous!.Next = node.Next;
}
else
{
Start = node.Next;
}
if (node != End)
{
node.Next!.Previous = node.Previous;
}
else
{
End = node.Previous;
}
Count--;
}
public IEnumerable<T> GetAllValues()
{
var counter = Start;
while (counter != null)
{
yield return counter.Value;
counter = counter.Next;
}
}
}
public class ListNode<T>
{
public T Value { get; }
public ListNode<T>? Previous { get; set; }
public ListNode<T>? Next { get; set; }
public ListNode(T value)
{
Value = value;
}
}
}

you can do something like this.
var recordsToRemove = dictionary.Where(x => x.Value.Contains("what you are looking for"))
.ToList();
if (recordsToRemove.Any())
{
foreach (var record in recordsToRemove)
{
dictionary.Remove(record.Key);
}
}

How to add nodes to my Child/Parent object?

I have an object below:
public class SubjectCategory : BaseModel
{
public decimal ParentSubjectCategoryId { get; set; }
public bool IsEnable { get; set; }
public virtual List<Subject>? Subjects { get; set; }
public virtual List<SubjectCategory>? ChildrenCategoris { get; set; }
public virtual SubjectCategory? ParentCategory { get; set; }
}
I get lists of subjectCategories from database (Picture Below).
I wrote a method that it adds ChildrenCategoris inside the categories which their ParentSubjectCategory Id is NULL or 0, but the problem is it is only works for the first level of tree!
public List<SubjectCategory> GetAllSubjectCategories()
{
var res = _subjectCategoryRepository.Select(new SubjectCategory {}).ToList();
List<SubjectCategory> newSubjectCategory = new List<SubjectCategory>();
foreach (var item in res)
{
if(item.ParentSubjectCategoryId != 0)
{
var a = newSubjectCategory.Where(sc => sc.Id ==
item.ParentSubjectCategoryId).FirstOrDefault();
if(a.ChildrenCategoris == null)
{
newSubjectCategory.Where(sc => sc.Id ==
item.ParentSubjectCategoryId).FirstOrDefault().ChildrenCategoris = new List<SubjectCategory>() { item};
}
else
{
newSubjectCategory.Where(sc => sc.Id == item.ParentSubjectCategoryId).FirstOrDefault().ChildrenCategoris.Add(item);
}
}
else
{
newSubjectCategory.Add(item);
}
}
return res;
}
But every child can have many ChildrenCategoris and their children can have many ChildrenCategoris as well and again.
the loop count is unknown.
how can I have a list with multiple children with C# ?

Linq query for the Multi list in singe out put

i have table looks like below
ID | Reason | PrID
-----------------
1 abc null
2 dhe null
3 aerc 1
4 dwes 2
5 adfje 1
i have class
public class Reason
{
public int Id { get; set; }
public string Reson{ get; set; }
public List<SecondryReason> SecReason{ get; set; }
public int? PrimaryId { get; set; }
}
public class SecondryReason
{
public int Id { get; set; }
public string Reason { get; set; }
public int PrimaryReasonId { get; set; }
}
I want this to be displayed in hierarchy level
if the prid is Null need to treat this as the parent remaining all child
i am trying Linq and unable to achieve this
Suggest me how to do this in an easy way in linq

So: You have a list/enumerable of type , whereof the SecReason List property is null. Then, using linq you want a list, were the only the "root" reasons remain, but the Sub-reasons got put in the lists, but as type SecondaryReason?
If so, I found this way to do it (linq and foreach):
static IEnumerable<Reason> GetReasonsGrouped(List<Reason> reasons)
{
var result = reasons.Where(x => x.PrimaryId == null);
foreach (var item in result)
{
item.SecReason = reasons.Where(x => x.PrimaryId == item.Id)
.Select(x => new SecondryReason()
{ Id = x.Id,
ReasonName = x.ReasonName,
PrimaryReasonId = item.Id
})
.ToList();
}
return result;
}
Or just linq, but harder to read:
var result = reasons.Where(x => x.PrimaryId == null)
.Select(x =>
{
x.SecReason = reasons.Where(r => x.PrimaryId == x.Id)
.Select(r => new SecondryReason()
{
Id = r.Id,
ReasonName = x.ReasonName,
PrimaryReasonId = x.Id
})
.ToList();
return x;
});

Not sure if linq will be the best solution, here is my proposed changes and method to get an Hierarchy type:
public class Reason
{
public int Id { get; set; }
public string Reson { get; set; }
public List<Reason> SecReason { get; set; }
public int? PrimaryId { get; set; }
//Adds child to this reason object or any of its children/grandchildren/... identified by primaryId
public bool addChild(int primaryId, Reason newChildNode)
{
if (Id.Equals(primaryId))
{
addChild(newChildNode);
return true;
}
else
{
if (SecReason != null)
{
foreach (Reason child in SecReason)
{
if (child.addChild(primaryId, newChildNode))
return true;
}
}
}
return false;
}
public void addChild(Reason child)
{
if (SecReason == null) SecReason = new List<Reason>();
SecReason.Add(child);
}
}
private List<Reason> GetReasonsHierarchy(List<Reason> reasons)
{
List<Reason> reasonsHierarchy = new List<Reason>();
foreach (Reason r in reasons)
{
bool parentFound = false;
if (r.PrimaryId != null)
{
foreach (Reason parent in reasonsHierarchy)
{
parentFound = parent.addChild(r.PrimaryId.Value, r);
if (parentFound) break;
}
}
if (!parentFound) reasonsHierarchy.Add(r);
}
return reasonsHierarchy;
}

C# Parse IF-ELSE Statement

UPDATE
I don´t want you to do my Work and write code for me I just wanted a nurge in the right Direction!
So I have to be more specific with my Problem, give me a chance to do some work on this and I will update my question with the results ;-)
UPDATE 2
I´ve solved my Problem with Roslyn maybe not very elegant but it work for my needs, here is the code ;-)
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Roslyn.Compilers;
using Roslyn.Compilers.CSharp;
namespace ParserTest
{
public class MyParser
{
private int _currentLevel = 1;
public void TestMethod()
{
string testString =
#" if(#ISEMPTY(temp.tis_filterstatus2))
{
tis_datasheet_selection.is_selected = 'Y'
}
else
{
if(#ISEMPTY(temp.tis_programmtyp_filter)) { }
else
{
AND tis_programme_v.type = '#SUB(temp.tis_programmtyp_filter)'
}
if(#ISEMPTY(temp.tis_programmfilter)) { }
else
{
AND tis_programme_v.programm LIKE '#SUB(temp.tis_programmfilter)%'
}";
var result = this.Parse(testString);
var finalResult = this.GenerateDsl(result);
}
public List<IfStatement> Parse(string strToParse)
{
var result = new List<IfStatement>();
var syntaxTree = SyntaxTree.ParseText(#"using System;class C{static void M(){" + strToParse + "}}");
var rootNodes = syntaxTree.GetRoot().DescendantNodes().Where(getRootNodes);
result = rootNodes.Select(n => ToIfStatement(n, null)).ToList();
ApplyNestingLevel(result);
return result;
}
private string GenerateDsl(List<IfStatement> list)
{
var sb = new StringBuilder();
foreach(var ifStmt in list)
{
IfStatementToDsl(ifStmt, sb);
}
return sb.ToString();
}
private string IfStatementToDsl(IfStatement ifStmt, StringBuilder sb)
{
string sqr = "";
for (int i = 0; i < ifStmt.Level; i++)
{
sqr += "'";
}
sb.Append("#IF(");
sb.Append(ifStmt.Condition.ApplyLevel(ifStmt.Level) + "," + sqr);
sb.Append(ifStmt.Statement.ApplyLevel(ifStmt.Level));
if(ifStmt.Childs.Count > 0)
{
foreach(var c in ifStmt.Childs)
{
IfStatementToDsl(c, sb);
}
}
sb.Append(sqr + "," + sqr);
if(ifStmt.Else != null)
{
sb.Append(ifStmt.Else.Statement.ApplyLevel(ifStmt.Level));
foreach(var c in ifStmt.Else.Childs)
{
IfStatementToDsl(c, sb);
}
}
sb.Append(sqr + ")");
return sb.ToString();
}
#region Parsing-Methods
private IfStatement ToIfStatement(SyntaxNode node, SyntaxNode parent)
{
var ifNode = (IfStatementSyntax)node;
var ifStmt = new IfStatement
{
Condition = ifNode.Condition.ToString(),
Statement = GetIfStatement(ifNode),
Childs = GetIfChilds(ifNode)
};
if (ifNode.Else != null)
{
ifStmt.Else = new ElseStatement
{
Statement = GetElseStatement(ifNode.Else),
Childs = GetElseChilds(ifNode.Else)
};
}
return ifStmt;
}
private List<IfStatement> GetIfChilds(IfStatementSyntax node)
{
var childs = node.Statement.DescendantNodes().Where(n => WhereIfNodes(n, node));
return childs.Select(n => ToIfStatement(n, node)).ToList();
}
private List<IfStatement> GetElseChilds(ElseClauseSyntax node)
{
var childs = node.Statement.DescendantNodes().Where(n => WhereElseNodes(n, node));
return childs.Select(n => ToIfStatement(n, node)).ToList();
}
private string GetIfStatement(IfStatementSyntax node)
{
var result = node.Statement.DescendantNodes().Where(n => WhereIfStatement(n, node));
string returnValue = "";
foreach (var n in result)
{
returnValue += n.ToString();
}
return returnValue.CleanString();
}
private string GetElseStatement(ElseClauseSyntax node)
{
var result = node.Statement.DescendantNodes().Where(n => WhereElseStatement(n, node));
string returnValue = "";
foreach (var n in result)
{
returnValue += n.ToString() + " ";
}
return returnValue.CleanString();
}
private void ApplyNestingLevel(List<IfStatement> list)
{
foreach (var item in list)
{
item.Level = _currentLevel;
if (item.Childs.Count > 0 || (item.Else != null && item.Else.Childs.Count > 0))
{
_currentLevel++;
}
ApplyNestingLevel(item.Childs);
if (item.Else != null)
{
ApplyNestingLevel(item.Else.Childs);
}
}
}
#endregion
#region Linq Where-Conditions
private bool WhereIfNodes(SyntaxNode node, IfStatementSyntax parent)
{
if(node.Kind == SyntaxKind.IfStatement && (node.Parent.Parent == parent))
{
return true;
}
return false;
}
private bool WhereElseNodes(SyntaxNode node, ElseClauseSyntax parent)
{
if (node.Kind == SyntaxKind.IfStatement && (node.Parent.Parent == parent))
{
return true;
}
return false;
}
private bool WhereIfStatement(SyntaxNode node, IfStatementSyntax parent)
{
if ((node.Kind == SyntaxKind.ExpressionStatement || node.Kind == SyntaxKind.LocalDeclarationStatement)
&& (node.Parent.Parent == parent))
{
return true;
}
return false;
}
private bool WhereElseStatement(SyntaxNode node, ElseClauseSyntax parent)
{
if ((node.Kind == SyntaxKind.ExpressionStatement || node.Kind == SyntaxKind.LocalDeclarationStatement)
&& (node.Parent.Parent == parent))
{
return true;
}
return false;
}
private Func<SyntaxNode, bool> getRootNodes =
n => n.Kind == SyntaxKind.IfStatement &&
(n.Parent.Parent.Kind != SyntaxKind.ElseClause && n.Parent.Parent.Kind != SyntaxKind.IfStatement);
#endregion
}
public class IfStatement
{
public int Level { get; set; }
public string Condition { get; set; }
public string Statement { get; set; }
public ElseStatement Else { get; set; }
public List<IfStatement> Childs { get; set; }
}
public class ElseStatement
{
public string Statement { get; set; }
public List<IfStatement> Childs { get; set; }
}
public static class Ext
{
public static string CleanString(this string value)
{
return value.Replace("\t", "").Replace("\n", "").Replace("\r", "");
}
public static string ApplyLevel(this string value, int level)
{
int multiplier = level * 2;
if (level == 0)
multiplier = 1;
var sb = new StringBuilder(multiplier);
for (int i = 0; i < multiplier; i++)
{
sb.Append("'");
}
return value.Replace("'", sb.ToString());
}
}
}
I have to write if-else Statements in a Domain-Specific-Language which is really a pain in the ass!
(The DSL is from a Third-Party-Tool which I have to use to generate WHERE-Statements for SQL-Queries)
Syntax:
#IF(#ISEMPTY(#SUB(temp.last_name))),'if true','else')
#SUB() reads a textboxvalue
Sample:
#IF(#ISEMPTY(#SUB(temp.last_name))),'','account_contact.last_name = ''DOE'' ')
you have to double your single-quotes in the else statement and if you want to nest different "if-else" every time you go a level deeper you have to double the doubled single-quotes!
You see it´s not very simple to write if you have complicated contitions...
So I thought I write a parser that transforms a normal if-else statement to this DSL-Syntax!
The Parser should create objects of this class:
public class IfCondition
{
public int ID { get; set; }
public int ParentID { get; set; }
public int Level { get; set; }
public string Condition { get; set; }
public string Content { get; set; }
public string ElseContent { get; set; }
}
based on a Collection of this Objects I could generate the DSL-Statements!
So my Problem is I really don´t have a clue, how to parse a String like this:
IF(#ISEMPTY(#SUB(temp.last_name))) { }
ELSE
{
IF(#SUB(temp.test) = 'Y')
{
account_contact.last_name = 'DOE'
}
ELSE
{
account_contat.first_name = "JOHN"
}
}
can somebody give me a nudge in the right direction?

If you use Roslyn for syntax rewritting. Not to just write about what you can do, here is an easy example.
Basically how it works. You create a syntax tree for your code and then use predefined visitors to visit those nodes you want to rewrite, you replace them by valid C# code and then you can compile this tree and make it work.
EDIT:
Another, more reliable source with an example

Statement is not updating data item

I have this LINQ statement that tries to set the 1st element in the collection of string[]. But it doesn't work.
Below is the LINQ statement.
docSpcItem.Where(x => x.DocID == 2146943)
.FirstOrDefault()
.FinishingOptionsDesc[0] = "new value";
public string[] FinishingOptionsDesc
{
get
{
if (this._FinishingOptionsDesc != null)
{
return (string[])this._FinishingOptionsDesc.ToArray(typeof(string));
}
return null;
}
set { this._FinishingOptionsDesc = new ArrayList(value); }
}
What's wrong with my LINQ statement above?

Couple of things.. There are some problems with your get and set. I would just use auto properties like this..
public class DocSpcItem
{
public string[] FinishingOptionsDesc { get; set; }
public int DocID { get; set; }
}
Next for your linq statement, depending on the presence of an item with an id of 2146943 you might be setting a new version of the object rather than the one you intended. This should work..
[TestMethod]
public void Linq()
{
var items = new List<DocSpcItem>();
//2146943
for (var i = 2146930; i <= 2146950; i++)
{
items.Add(new DocSpcItem()
{ DocID = i
, FinishingOptionsDesc = new string[]
{ i.ToString() }
}
);
}
var item = items.FirstOrDefault(i => i.DocID == 2146943);
if (item != null)
{
item.FinishingOptionsDesc = new string[]{"The New Value"};
}
}
and
public class DocSpcItem
{
public string[] FinishingOptionsDesc { get; set; }
public int DocID { get; set; }
}