Updating a table variable
When a new course entity is created, it must have a relationship to an existing department.To facilitate this, the scaffolded code includes controller methods and Create and Edit views that include a drop-down list for selecting the department.Keys are unique within a dictionary while values may not be.The values of a dictionary can be of any type, but the keys must be of an immutable data type such as strings, numbers, or tuples.Create [Http Post] [Validate Anti Forgery Token] public Action Result Edit(int id, Form Collection form Collection, string selected Courses) private void Update Instructor Courses(string selected Courses, Instructor instructor To Update) The code then loops through all courses in the database and checks each course against the ones currently assigned to the instructor versus the ones that were selected in the view.To facilitate efficient lookups, the latter two collections are stored in This code creates an HTML table that has three columns.To access dictionary elements, you can use the familiar square brackets along with the key to obtain its value.
To explicitly remove an entire dictionary, just use the del statement. /usr/bin/python dict = del dict['Name']; # remove entry with key 'Name' dict.clear(); # remove all entries in dict del dict ; # delete entire dictionary print "dict['Age']: ", dict['Age'] print "dict['School']: ", dict['School'] Note − del() method is discussed in subsequent section. They can be any arbitrary Python object, either standard objects or user-defined objects. There are two important points to remember about dictionary keys − (a) More than one entry per key not allowed. When duplicate keys encountered during assignment, the last assignment wins.For many-to-many relationships, the Entity Framework doesn't expose the join table directly, so you must explicitly add and remove entities to and from the appropriate navigation properties.The following illustrations show the pages that you'll work with.Run the Create page (display the Course Index page and click Create New) and enter data for a new course: Click Create.The Course Index page is displayed with the new course added to the list.