To keep things organized, folders are created to store the C# files that represent models and data handlers. Models are C# classes that define entity structure. Each class usually maps directly to a database table. Some types of databases (called no-SQL) do not have tables per se. That is why we refer to the model class as an entity and not specifically a table. All the models will go in the Models folder.
The models are simple C# classes with the name representing an entity. Think of this as a spreadsheet with tables that have columns with header names and rows with data. Each sheet is an entity. Each column in the sheet has a name. The property names in the model class are the same as the spreadsheet column names. They represent the schema. One difference is that each property must have a data type. That is a basic premise of the strongly typed C# approach. Each property has a getter and setter which means it can be written to and read from. An example model class would look like this:
public class Student { public string ID { get; set; } public string Name { get; set; } }
Instructions
A folder called Models already exists. Edit the file called Continent.cs in the Models folder. Add the namespace for our project. This would be the project name, RazorCountry
, followed by the folder path.
Define a public class with the name Continent
. This goes inside the namespace.
Define public string fields for ID
and Name
. Don’t forget the getter and setter.
A folder called Models already exists. Edit the file called Country.cs in the Models folder. Add a using
statement that supports System
data types.
Add the namespace for our project. This is the same as you did for Continent.cs.
Define a public class named Country
. This goes inside the namespace.
Add six public fields inside the class definition:
ID
,ContinentID
, andName
are strings.Population
andArea
are nullable ints.UnitedNationsDate
is a nullable date.
Make a type nullable by adding a question mark. For example, bool?
is a nullable boolean.