에서 중복 항목을 삭제 한

Question

사람이 같은 항목이 I가 LinqPad를 사용하여 작은 프로그램을 작성

DataTable freeTechslist = user.GetAllUsers(); 
DataTable assignedtechsList = Task.GetAllAssignedUserToTask(taskID); 

foreach(DataRow row1 in freeTechslist.Rows) 
{ 
    foreach(DataRow row2 in assignedtechsList.Rows) 
    { 
     var arr1 = row1.ItemArray; 
     var arr2 = row2.ItemArray; 
     if (arr2.SequenceEqual(arr1)) 
     { 
      int num = arr1.Count(); 
      freeTechslist.Rows[num].Delete();  
     } 
    } 
} 

return freeTechslist; 

Answer 1

assignedtechsList 데이터 테이블에 포함되어있는 경우 내가 freeTechslist 데이터 테이블에서 중복 항목을 삭제하려고 내 코드를 도와 줄 수있는 데이터 테이블 Linq의 역할에 대해 설명하십시오. GetAllUsers 및 GetAllAssignedUserToTask의 구현은 설명의 목적으로 중요하지 않습니다. 난 그냥 코드에서 사용하는 것처럼 DataTable을 반환하는 샘플 함수를 만들었습니다. 또한 Guids를 기술자의 식별자로 사용하도록 코드를 수정했습니다.

void Main() 
{ 
    var allTechs = GetAllUsers(); 
    var freeTechsList = 
      //Start the Linq query by selecting all the available techs. 
      //Since GetAllUsers returns a DataTable, we use AsEnumerable 
      //to convert the DataTable to a queryable object 
      from tech in allTechs.AsEnumerable() 
      //Now we add a where clause to the Linq query. Essentially 
      //what this clause does is just remove every tech that is in 
      //the assigned techs list (which is returned by GetAllAssignedUserToTask) 
      where 
      !(
       //This is our subquery; all this does is give us a list of Guids 
       //that identifies techs that are assigned. Again, GetAllAssignedUserToTask 
       //returns a DataTable, so we use AsEnumerable to make it queryable with Linq 
       from assigned in GetAllAssignedUserToTask(allTechs).AsEnumerable() 
       select assigned.Field<Guid>("TechGUID") 
      //The above subquery has returned us a list of assigned techs, so we check if 
      //the current tech we're looking at from GetAllUsers is in that list using 
      //the Contains method. Contains will tell us whether the current tech is in the 
      //list of assigned techs. Since we negate the result above (using !), that means 
      //that if the tech is in this list, he will not be included in the final result. 
      ).Contains(tech.Field<Guid>("TechGUID")) 
      //Finally, we return the selected techs that have been filtered by our where clause 
      select tech; 

    //Dump is basically just LinqPad's version of print so we can see the result.   
    freeTechsList.Dump(); 
} 

// Define other methods and classes here 
DataTable GetAllUsers() 
{ 
    //create a datatable 
    var dt = new DataTable(); 
    dt.Columns.Add(new DataColumn() {DataType = typeof(Guid), ColumnName = "TechGUID"}); 
    dt.Columns.Add(new DataColumn() {DataType = typeof(String), ColumnName = "Name"}); 

    //add some data 
    DataRow bob = dt.NewRow(); 
    bob["Name"] = "Bob"; 
    bob["TechGUID"] = Guid.NewGuid(); 
    dt.Rows.Add(bob); 

    DataRow phil = dt.NewRow(); 
    phil["Name"] = "Phil"; 
    phil["TechGUID"] = Guid.NewGuid(); 
    dt.Rows.Add(phil); 

    DataRow joe = dt.NewRow(); 
    joe["Name"] = "Joe"; 
    joe["TechGUID"] = Guid.NewGuid(); 
    dt.Rows.Add(joe); 

    return dt; 

} 

DataTable GetAllAssignedUserToTask(DataTable allUsers) 
{ 
    //simulate Joe as our only assigned Tech 
    return allUsers.AsEnumerable() 
        .Where(tech => tech.Field<String>("Name") == "Joe") 
        .CopyToDataTable(); 
}