cannot convert from int to Models.employeecourse error

ahmed salah

10y1.2kLINQ

how to loop and delete record from database in table EmployeeCourse table

this is my code

when itry to delete record from removedCourseIds collection it give me error

cannot convert from int to Models.employeecourse

[HttpPost]
ic ActionResult Edit(EditEmployeeVm model)
{
var existingCourseIds = db.EmployeeCourses.Where(g => g.EmployeeId == model.Id && g.CourseId!=null)
.Select(f => f.CourseId.Value).ToList();
var removedCourseIds = existingCourseIds.Except(model.CourseIds);
//Now loop through these and delete it from db
foreach (var removedCourseId in removedCourseIds)
{
//here error show in variable removedCourseId and show red line under this variable in line of remove
db.EmployeeCourses.Remove(removedCourseId);
}
db.SaveChanges();
return View();
}

5 Replies

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ahmed salah10y ago
db.EmployeeCourses.Remove(x => x.CourseId == removedCourseId);
I implement this and give me error
cannot convert lambda expression to employeecourse because it is not delegate type
ahmed salah10y ago
1. db.EmployeeCourses.RemoveRange(db.EmployeeCourses.Where(c => idlist.Contains(Id)));
i implement the statment above it delete all record found in employeecourse table
and this is not needed
Manas Mohapatra10y ago
Try like below:
foreach (var removedCourseId in removedCourseIds)
{
    db.EmployeeCourses.Remove(x => x.CourseId == removedCourseId);
}

// OR

db.EmployeeCourses.RemoveRange(db.EmployeeCourses.Where(c => idlist.Contains(Id)));
ahmed salah10y ago
in modelmodel.CourseIds
CourseIdsas following
public int[] CourseIds { set; get; }
all model as following
public class EditEmployeeVm
{
public int Id { set; get; }
public string Name { get; set; }
public List Courses { get; set; }
public int[] CourseIds { set; get; }
public List ExistingCourses { set; get; }
}
Manas Mohapatra10y ago
The issue you are getting due to following code;

var existingCourseIds = db.EmployeeCourses.Where(g => g.EmployeeId == model.Id && g.CourseId!=null).Select(f => f.CourseId.Value).ToList();

var removedCourseIds = existingCourseIds.Except(model.CourseIds);

Please make sure both are same datatype. That means existingCourseIds is list of integer and same way model.CourseIds should be list of integer.

If both are different then make it list of integer or strings as per requirement.