How to use same model with less fields for another view in mvc5 - model-view-controller

Question

My Question is not belonging to how to use two models on same razor view ! basically I have a user table in which i have fields like(userid,name,email,password,gender,country,department,IsActive) and my form is working fine i am able to insert update and delete i have not use EF , what i did i create the table in sql server and create the model in my model folder , in my view i have put the required field validator for all these columns and they are mandatory to input while inserting or updating.
Now I want to have another view with another controller where i do not want to show all 8 fields instead want to show just these four columns( username,email,gender,IsActive)
when i am using the same model for the other controller and view then it loads the record correctly on index view ,but when i update the required it fires validation error as all my fields are mark as required so it ask to input the rest of four fields value as well.
I have tried to remove these un-necessary fields from model in controller code before saving using Bind([Exclude]"""") but it did not work.
I have tried modelstate.remove("") this approach works fine for all fields but my password field is still throwing validation error . someone says you need to use viewmodel and in viewmodel you have to put both of your model like the full model and small model, I want to ask how my small model would be mapped to my user table (as table["tableName"] this cannot be applied to two models and pointing to same table without primary foriegn key relation .
Share example please i am confused
modelState.Remove("Password")
This remove all model values which are un-necessary but not removing the password field which gives error while updating the

Answer 1

You have required fields missing data or some fields are not null when being saved. What you are trying to do is completely ok. You are basically using a Virtual Model. This is what I do. In the "get", you fix your model and send it to the view. You work with it and then when you submit, you receive the model in the "post", but it is missing several REQUIRED fields. So what you need to do is, retrieve the same record from the database, update the 3 or 4 fields from the view model and then save that model that you retrieved with the new data. This is one way. (VM = view model)
1. send VM to view
2. add data in the view
3. submit
4. receive VM in POST Controller
5. get same record from DB
6. update the particular fields using the VM data
7. save the updated record to database. This is the record you retrieved in 5.
Another way is to have all the missing fields in the model but not showing them in the view. However you need to mention them in the view, otherwise they will not post. so you need to use
#Html.Hidefor( x=> x.NameOfField)
This will ensure that the field is sent back for posting. Any field with a [Required]... is required. You cannot miss it!
How will your small model be mapped to the Database. It will not. You will transfer the data from the small model to the model that is mapped in the database... with ALL the fields. Either you get the missing values from the database or from the view by using Hidefor.
example
dbmodel.Field1 = vm.field1;
dbmodel.Field2 = vm.field2;
dbmodel.Field3 = vm.field3;
I hope this helps