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();
}
Expression <Func <Enrollment, EnrollmentBaseModel> > ISelectExpression <Enrollment, EnrollmentBaseModel> .GetSelectExpression()
{
Expression <Func <Enrollment, EnrollmentBaseModel> > select = enrollment => new EnrollmentBaseModel
{
EnrollmentId = enrollment.EnrollmentID,
Grade = enrollment.Grade,
};
select = select.AddMemberInit(e => e.Grade, r => r.GradeString, EnumExpressionExtensions.GetEnumToStringExpression <Grade?>(g => g.ToString()));
return(select);
}
