Sometimes when you work on
entity model (edmx) and want to add a view or table that doesn't have a primary
key or non-nullable field (this case specially arise when you add a view to the
model), then you end up with warning message says:
"Error 6013: The table/view does not have a primary
key defined and no valid primary key could be inferred"
I have googled it, and the
answer was to modify the edmx xml file () to add this view manually
to the edmx.
The steps are
straightforward, but need to copy paste the solution when ever you want to
update the model which will override your modified code. So rule #1 in this
post is:
"When you do some manual modifications to the edmx file, you
must take a copy of the text before updating the model".
ok, let say that you have
a view which shows the number of students in each faculty in the university
named INV (Institute of Nano Velocity).
the View name
is: V_INV_TOTAL_STU, which has columns:
FAC_CODE: number.
FAC_NAME: Varchar2 (max: 4000 bytes).
TOTAL: number.
Now the following will
show how to work manually with EF5 and edmx model file.
Step1:
Try to add the view from
the update model option in the edmx file automatically, or at least try to.
If the above error (6013)
appeared then right click the edmx file and choose edit with XML Editor
When the edmx opened in
xml do the following:
1. Uncomment the
entitytype generated automatically in the
Note:
nullable="false" must be added to the property so that FAC_CODE will
be the key of the view.
2. Add the following code in the
3. in the
at the tag add the
following:
4. Add the
following Code in the :
Note:
this will map the column name to the corresponding property in the model.
Save the edmx file.
Step2:
Now its time to map or
bind this view to its corresponding model, so create a new class in the models
folder named V_INV_TOTAL.cs.
then add the following
properties to it:
public int FAC_CODE { get; set; }
public string FAC_NAME { get; set; }
public Int64 TOTAL_REQUESTS { get; set; }
Step3:
The last step is to modify
the model.context.cs file which will connect to the DB.
add this code to its
properties:
public
DbSet V_INV_TOTAL_REQUESTS { get; set; }.
Now you are ready to work
on with this new model in your controllers and views.
Again I want to remind you
to take a copy of the modified edmx and context files generated automatically
when you create the edmx model for the first time, because once you want to
update the model, then these files will be overwritten.... so be careful.
references:
Also i have found this
tool from VisualStudio 2013 team, hope it will much easier than the steps
provided in this post:
