generate mapping for one to many entites about gridify HOT 9 CLOSED

Your query is wrong, you need to start from your collection (course) and manually map parent class properties. in the above example, you're doing it in reverse order.
also, gridify just converting your string to the actual expression, you should at least provide a Linq example of what you need to achieve.

from gridify.

from st in db.students
where st.courses.where(x=>x.name=="abcd").count()>0
select st

I am on students page ,that has a data grid.
user want filter students grid by it condition

from gridify.

exactly, if you have a two-way relation between students and courses you can simply switch your collections.
e.g:

var query = from course in db.courses
where course.Name == "abcd"
select course.Student

this way you can use gridify without problem because your query is normalized now. this query does exactly what you want.
and this way because your student relation is not a collection you can Add your mappings for the student entity.

var gm = new GridifyMapper<Course>()
                    .AddMap("CourseName", x=> x.Name)
                    .AddMap("StudentName", x=> x.Student.Name)
                   ....
              

In the end, you should use Projection or select statement to get the students

from gridify.

Ok.
How do you do If i want add other conditiones related with student in one query ?
Tnx a lot

from gridify.

e.g

var gq = new GridifyQuery() { Filter = "Age<30 , StudentName^a ,  CourseName==abcd" , SortBy = "StudentName" };
var gm = new GridifyMapper<Course>()
                    .AddMap("CourseName", x=> x.Name)
                    .AddMap("StudentName", x=> x.Student.Name)
                    .AddMap("Age" , x=>  x.Student.Age);

var query = db.Courses.ApplyFilterAndOrdering( gq ); // or use GridifyQueriable if you need pagination too
var result = query.Select(x=> x.Student).ToList(); // you can select anything here

from gridify.

tnx a lot
but a question !
what is query ?
get all students list! that can filter by multiple field by user! the customer wants me a filter on same list over related table( course)
with this solution i get all students that select minimum one course
this is not all real students list
Is that right?

from gridify.

Yes, it depends on what you want exactly there are few ways to write a single query. in this case, your main query was on CourseName so it makes sense to select students related to the courses.
usually, if you want to select all students you shouldn't use filtering on courses.
these tricks help you implement 99 percent of scenarios, but I agree there are some edge cases you can't do much. (I never faced one yet though).

from gridify.

tnx a lot for replay

from gridify.

Your requested feature is available in the v2.

from gridify.