比较两个列值以及匹配和不匹配记录的计数 [英] Compare two column values and count of the matched and unmatched records

问题描述

我有一个表格（记录），如

 Id Data1 Data2 
 1 AB 
 2 CC 
 3 DD 
 4 BA 
 5 CD 
 6 AA 
 7 DD 

我需要匹配的行数（匹配= 4& ;无与伦比= 3）使用实体框架



我完成了如下代码。我得到了我期望的结果，我需要避免性能以及代码减少。

  int  correctAnswersCount =  0 ; 
  int  incorrectAnswersCount =  0 ; 
  int  totalUnAttemptsCount =  0 ; 
  string  [] aa =（ from  a  in  db.ALBulkTestResults 其中 a.CandidateID == candidateId 选择 a.Answer）.ToArray （）; 
  string  [] bb =（来自 a  in  db.ALBulkTestResults 其中 a.CandidateID == candidateId  select  a.CandidateAns）。ToArray （）; 
 
  for （ int  i =  0 ; i< aa.Length; i ++）
 {
  string  comp1 = aa [i]; 
  string  comp2 = bb [i]; 
  if （comp1 == comp2）
 {
 ViewData [  correctAnswersCount] = correctAnswersCount ++; 
} 
  else  
 {
  if （comp2 ==   N）
 {
 ViewData [  totalUnAttemptsCount] = totalUnAttemptsCount ++; 
} 
  else  
 {
 ViewData [  incorrectAnswersCount] = incorrectAnswersCount ++; 
} 
} 
} 
 

解决方案

是的，你可以实现同样的目标通过编写非常简单的LINQ查询。

代码示例如下：

 namespace ConsoleApp 
 {
 class Program 
 {
 static void Main（string [] args）
 {
 Customer cust = new Customer（）; 
 
列表<客户> custList = cust.GetCustomerData（）; 
 int matchedCount = custList.Where（p => p.Data1 == p.Data2）.Count（）; 
 int unmatchedCount = custList.Where（p => p.Data1！= p.Data2）.Count（）; 
} 
} 
 
公共类客户
 {
 public int Id {get;组; } 
 public string Data1 {get;组; } 
 public string Data2 {get;组; } 
 
 public List< Customer> GetCustomerData（）
 {
返回新列表< Customer> {
 new Customer（）{Id = 1，Data1 =A，Data2 =B}，
 new Customer（）{Id = 2，Data1 =C，Data2 =C }，
新客户（）{Id = 3，Data1 =D，Data2 =D}，
新客户（）{Id = 1，Data1 =B，Data2 = A}，
新客户（）{Id = 1，Data1 =C，Data2 =D}，
新客户（）{Id = 1，Data1 =A， Data2 =A}，
 new Customer（）{Id = 1，Data1 =A，Data2 =B}，
 new Customer（）{Id = 1，Data1 =D ，Data2 =D} 
}; 
} 
} 
} 

你正在做很多额外的工作。

主要是减少一次通过数据。

另外，在分析结束前不要更新 ViewData 。 br />

  int  correctAnswersCount =  0 ; 
  int  incorrectAnswersCount =  0 ; 
  int  totalUnAttemptsCount =  0 ; 
  const   string  NoAttempt =   N; 
  foreach （ var  a  in  db.ALBulkTestResults）
 {
  string  candidateAnswer = a.CandidateAns; 
  if （candidateAnswer == a.Answer）
 {
 ++ correctAnswersCount; 
} 
  else   if （candidateAnswer == NoAttempt）
 { 
 ++ totalUnAttemptsCount; 
} 
  else  
 {
 ++ incorrectAnswersCount; 
} 
} 
 ViewData [  correctAnswersCount] = correctAnswersCount ; 
 ViewData [  totalUnAttemptsCount] = totalUnAttemptsCount; 
 ViewData [  incorrectAnswersCount] = incorrectAnswersCount; 

I have table(Records) like an

Id  Data1 Data2
1     A     B
2     C     C
3     D     D
4     B     A
5     C     D
6     A     A
7     D     D

I need the Count of matched rows like (matched = 4 & unmatched = 3) using Entity Framework

and i have done the code like below. and i got what i expected result and i need to avoid the performance as well code reducing.

int correctAnswersCount = 0;
int incorrectAnswersCount = 0;
int totalUnAttemptsCount = 0;
string[] aa = (from a in db.ALBulkTestResults where a.CandidateID == candidateId select a.Answer).ToArray();
string[] bb = (from a in db.ALBulkTestResults where a.CandidateID == candidateId select a.CandidateAns).ToArray();

for (int i=0; i<aa.Length; i++ )
{
    string comp1 = aa[i];
    string comp2 = bb[i];
    if(comp1 == comp2)
    {
        ViewData["correctAnswersCount"] = correctAnswersCount++;
    }
    else
    {
        if (comp2 == "N")
        {
            ViewData["totalUnAttemptsCount"] = totalUnAttemptsCount++;
        }
        else
        {
            ViewData["incorrectAnswersCount"] = incorrectAnswersCount++;
        }
    }
}

解决方案

Yes, you can achieve the same by writing very simple LINQ query.
Code sample is given below:

   namespace ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Customer cust = new Customer();

            List<Customer> custList = cust.GetCustomerData();
            int matchedCount = custList.Where(p => p.Data1 == p.Data2).Count();
            int unmatchedCount = custList.Where(p => p.Data1 != p.Data2).Count();
        }
    }

    public class Customer
    {
        public int Id { get; set; }
        public string Data1 { get; set; }
        public string Data2 { get; set; }

        public List<Customer> GetCustomerData()
        {
            return new List<Customer> {
                 new Customer () {  Id = 1, Data1 = "A",Data2 = "B"},
                 new Customer () {  Id = 2, Data1 = "C",Data2 = "C"},
                 new Customer () {  Id = 3, Data1 = "D",Data2 = "D"},
                 new Customer () {  Id = 1, Data1 = "B",Data2 = "A"},
                 new Customer () {  Id = 1, Data1 = "C",Data2 = "D"},
                 new Customer () {  Id = 1, Data1 = "A",Data2 = "A"},
                 new Customer () {  Id = 1, Data1 = "A",Data2 = "B"},
                 new Customer () {  Id = 1, Data1 = "D",Data2 = "D"} 
            };
        }
    }
}

You are doing a lot of extra work.
The main thing is to reduce to a single pass through the data.
Also, don't update ViewData until the end of the analysis.

int correctAnswersCount = 0;
int incorrectAnswersCount = 0;
int totalUnAttemptsCount = 0;
const string NoAttempt = "N"; 
foreach (var a in db.ALBulkTestResults) 
{
    string candidateAnswer = a.CandidateAns;
    if (candidateAnswer == a.Answer)
    {
        ++correctAnswersCount;
    }
    else if (candidateAnswer == NoAttempt)
    {
        ++totalUnAttemptsCount;
    }
    else
    {
        ++incorrectAnswersCount;
    }
}
ViewData["correctAnswersCount"] = correctAnswersCount;
ViewData["totalUnAttemptsCount"] = totalUnAttemptsCount;
ViewData["incorrectAnswersCount"] = incorrectAnswersCount;

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