public static void CombineSelectExpression(SchoolContext ctx)
{
Expression<Func<Course, CourseModel>> courseSelect =
course => new CourseModel
{
CourseId = course.CourseID,
Title = course.Title,
Credits = course.Credits
};
Expression<Func<Enrollment, EnrollmentBaseModel>> enrollmentSelect =
enrollment => new EnrollmentBaseModel
{
EnrollmentId = enrollment.EnrollmentID,
Grade = enrollment.Grade
};
Expression<Func<Student, StudentModel>> studentSelect =
student => new StudentModel
{
StudentId = student.ID,
FirstMidName = student.FirstMidName,
LastName = student.LastName
};
Expression<Func<Enrollment, CourseEnrollmentModel>> enrollmentWithStudentsSelect =
enrollment => new CourseEnrollmentModel
{
};
enrollmentWithStudentsSelect = enrollmentWithStudentsSelect.InheritInit(enrollmentSelect);
enrollmentWithStudentsSelect = enrollmentWithStudentsSelect.AddMemberInit(
enrollmentEntity => enrollmentEntity.Student,
enrollmentModel => enrollmentModel.Student,
studentSelect
);
enrollmentWithStudentsSelect = enrollmentWithStudentsSelect.AddMemberInit(
enrollmentEntity => enrollmentEntity.Grade,
enrollmentModel => enrollmentModel.GradeString,
EnumExpressionExtensions.GetEnumToStringExpression<Grade?>(grade => grade.ToString())
);
Expression<Func<Course, CourseFullModel>> courseFullSelect =
course => new CourseFullModel
{
};
courseFullSelect = courseFullSelect.InheritInit(courseSelect);
courseFullSelect = courseFullSelect.AddMemberInit(
courseEntity => courseEntity.Enrollments,
courseModel => courseModel.Enrollments,
enrollmentWithStudentsSelect
);
var courses = ctx.Courses.Select(courseFullSelect).ToList();
}
static void Main(string[] args)
{
AppDomain.CurrentDomain.SetData("DataDirectory", Path.GetFullPath("..\\..\\App_Data"));
using (SchoolContext ctx = new SchoolContext())
{
HowWeDid(ctx);
HowWeDo(ctx);
PropertiesMapperExample(ctx);
ExpressionsCombinationExample.CombineSelectExpression(ctx);
SimpleSelect.ShowStudents(ctx);
SelectNonCache.ShowStudents(ctx);
InitInheritanceExample.ShowCourses(ctx);
MemberInitExample.ShowStudents(ctx);
CultureResolveExample.ShowCourses(ctx);
FilterExpression.FilterStudents(ctx);
}
Console.ReadKey();
}
private static void HowWeDid(SchoolContext ctx)
{
var students = ctx.Students.Select(s => new StudentModel
{
StudentId = s.ID,
FirstMidName = s.FirstMidName,
LastName = s.LastName,
EnrollmentDate = s.EnrollmentDate
})
.ToList();
Console.WriteLine(GetResultsString("Students", students));
//Reuse
var studentsInOtherController = ctx.Students.Where(s => SqlFunctions.DateDiff("year", s.EnrollmentDate, DateTime.Now) < 12)
.Select(s => new StudentModel
{
StudentId = s.ID,
FirstMidName = s.FirstMidName,
LastName = s.LastName,
EnrollmentDate = s.EnrollmentDate
})
.ToList();
Console.WriteLine(GetResultsString("Other Students", studentsInOtherController));
Expression<Func<Enrollment, EnrollmentBaseModel>> enrollmentSelect = enrollment => new EnrollmentBaseModel
{
EnrollmentId = enrollment.EnrollmentID,
Grade = enrollment.Grade
};
var enrollments1 = ctx.Enrollments.Select(enrollmentSelect).ToList();
Console.WriteLine(GetResultsString("Enrollment1", enrollments1));
var enrollments2 = ctx.Enrollments.Where(e => e.Grade != null).Select(enrollmentSelect).ToList();
Console.WriteLine(GetResultsString("Enrollment2", enrollments2));
var courses = ctx.Courses.Select(course => new CourseFullModel
{
CourseId = course.CourseID,
Title = course.Title,
Credits = course.Credits,
Enrollments = course.Enrollments.Select(
enrollment => new CourseEnrollmentModel
{
EnrollmentId = enrollment.EnrollmentID,
Grade = enrollment.Grade,
GradeString = enrollment.Grade == null
? null
: enrollment.Grade == Grade.A ? Grade.A.ToString()
: enrollment.Grade == Grade.B ? Grade.B.ToString()
: enrollment.Grade == Grade.C ? Grade.C.ToString()
: enrollment.Grade == Grade.D ? Grade.D.ToString()
: enrollment.Grade == Grade.F ? Grade.F.ToString()
: null,
Student = new StudentModel
{
FirstMidName = enrollment.Student.FirstMidName,
LastName = enrollment.Student.LastName,
EnrollmentDate = enrollment.Student.EnrollmentDate,
StudentId = enrollment.Student.ID
}
})
});
Console.WriteLine(GetResultsString("Courses", courses));
}
private static void PropertiesMapperExample(SchoolContext ctx)
{
var enrollments = ctx.Enrollments.ToList();
var enrollmentModel = Mapper.Map<Enrollment, EnrollmentModel>(enrollments[0]);
Console.WriteLine(enrollmentModel);
var enrollmentModels = enrollments.MapSelect<Enrollment, EnrollmentModel>().ToList();
Console.WriteLine(GetResultsString("Enrollments", enrollmentModels));
}
private static void HowWeDo(SchoolContext ctx)
{
var students = ctx.Students.ResolveSelect<Student, StudentModel>().ToList();
Console.WriteLine(GetResultsString("Students", students));
var studentsInOtherController = ctx.Students.Where(s => SqlFunctions.DateDiff("year", s.EnrollmentDate, DateTime.Now) < 12)
.ResolveSelectExternal<Student, StudentModel>();
Console.WriteLine(GetResultsString("Other Students", studentsInOtherController));
var enrollments1 = ctx.Enrollments.ResolveSelect<Enrollment, EnrollmentBaseModel>().ToList();
Console.WriteLine(GetResultsString("Enrollment1", enrollments1));
var enrollments2 = ctx.Enrollments.Where(e => e.Grade != null).ResolveSelectExternal<Enrollment, EnrollmentBaseModel>().ToList();
Console.WriteLine(GetResultsString("Enrollment2", enrollments2));
var courses = ctx.Courses.ResolveSelectExternal<Course, CourseFullModel>().ToList();
Console.WriteLine(GetResultsString("Courses", courses));
var courseWithStudents = ctx.Courses.ResolveSelectExternal<Course, CourseWithOldStudentsModel>().ToList();
Console.WriteLine(GetResultsString("Courses with students", courseWithStudents));
}