public async Task <List <StudentDto> > GetStudents(GetStudentsFilter filter)
{
GetStudentsFilter = filter;
await Task.CompletedTask;
return(Students);
}
public async Task <List <StudentDto> > GetStudents(GetStudentsFilter filter)
{
var query = students.AsQueryable();
if (filter.NumberOfCourses.HasValue)
{
query = query.Where(x => x.Enrollments.Count == filter.NumberOfCourses.Value);
}
if (filter.EnrolledIn.HasValue)
{
query = query.Where(x =>
x.Enrollments.Any(e => e.CourseId == filter.EnrolledIn.Value));
}
return(await query
.Include(x => x.Enrollments)
.Select(x => new StudentDto
{
Id = x.Id,
Name = x.Name.Name,
Email = x.Email.Address,
Enrollments = x.Enrollments.Select(e => new EnrollmentDto
{
Course = courses
.Select(c => new CourseDto
{
Id = c.Id,
Title = c.Title.Title,
Credits = c.Credits.Amount,
})
.First(c => c.Id == e.CourseId),
Grade = e.Grade.ToString(),
}).ToList()
})
.ToListAsync());
}
public async Task <List <StudentDto> > GetStudents(GetStudentsFilter filter)
{
using (var conn = Connection)
{
var query = @"
SELECT
s.Id,
s.Name,
s.Email,
e.Grade,
c.Id as CourseId,
c.Title,
c.Credits
FROM
Students s
LEFT JOIN Enrollment e ON s.Id = e.StudentId
LEFT JOIN Courses c ON e.CourseId = c.Id";
var rows = await conn.QueryAsync <StudentCourseRow>(query);
var students = new Dictionary <Guid, StudentDto>();
foreach (var row in rows)
{
if (!students.ContainsKey(row.Id))
{
var student = new StudentDto
{
Id = row.Id,
Name = row.Name,
Email = row.Email,
};
students.Add(row.Id, student);
if (row.CourseId != Guid.Empty)
{
student.Enrollments.Add(new EnrollmentDto
{
Course = new CourseDto
{
Id = row.CourseId,
Title = row.Title,
Credits = row.Credits,
},
Grade = row.Grade
});
}
}
else
{
students[row.Id].Enrollments.Add(new EnrollmentDto
{
Course = new CourseDto
{
Id = row.CourseId,
Title = row.Title,
Credits = row.Credits,
},
Grade = row.Grade
});
}
}
var result = students.Values.ToList();
if (filter.NumberOfCourses.HasValue)
{
result = result.Where(x => x.Enrollments.Count == filter.NumberOfCourses.Value).ToList();
}
if (filter.EnrolledIn.HasValue)
{
result = result.Where(x =>
x.Enrollments.Any(e => e.Course.Id == filter.EnrolledIn.Value)).ToList();
}
return(result);
}
}