InAutodesk released a white paper entitled "Building Information Modeling,"  and other software vendors also started to assert their involvement in the field. Building Information Modeling BIM is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle; defined as existing from earliest conception to demolition. Building information modeling extends this beyond 3Daugmenting the three primary spatial dimensions width, height and depth with time as the fourth dimension 4D  and cost as the fifth 5D.
The Razor Pages tutorial has been updated with the following improvements: Is easier to follow. For example, the scaffolding code has been significantly simplified. Provides more EF Core best practices.
Uses more efficient queries. For information about the tutorial series, see the first tutorial in the series. In the previous tutorials, you worked with a simple data model that was composed of three entities. In this tutorial, you'll add more entities and relationships and you'll customize the data model by specifying formatting, validation, and database mapping rules.
When you're finished, the entity classes will make up the completed data model that's shown in the following illustration: Customize the Data Model by Using Attributes In this section you'll see how to customize the data model by using attributes that specify formatting, validation, and database mapping rules.
Then in several of the following sections you'll create the complete School data model by adding attributes to the classes you already created and creating new classes for the remaining entity types in the model. The DataType attribute For student enrollment dates, all of the web pages currently display the time along with the date, although all you care about for this field is the date.
By using data annotation attributes, you can make one code change that will fix the display format in every view that shows the data. To see an example of how to do that, you'll add an attribute to the EnrollmentDate property in the Student class.
DataAnnotations namespace and add DataType and DisplayFormat attributes to the EnrollmentDate property, as shown in the following example: In this case we only want to keep track of the date, not the date and time. The DataType attribute can also enable the application to automatically provide type-specific features.
For example, a mailto: EmailAddress, and a date selector can be provided for DataType. Date in browsers that support HTML5.
The DataType attributes don't provide any validation. Date doesn't specify the format of the date that's displayed. By default, the data field is displayed according to the default formats based on the server's CultureInfo. The DisplayFormat attribute is used to explicitly specify the date format: You might not want that for some fields -- for example, for currency values, you might not want the currency symbol in the text box for editing.
You can use the DisplayFormat attribute by itself, but it's generally a good idea to use the DataType attribute also. The DataType attribute conveys the semantics of the data as opposed to how to render it on a screen, and provides the following benefits that you don't get with DisplayFormat: The browser can enable HTML5 features for example to show a calendar control, the locale-appropriate currency symbol, email links, some client-side input validation, etc.
By default, the browser will render data using the correct format based on your locale. Run the app, go to the Students Index page and notice that times are no longer displayed for the enrollment dates.
The same will be true for any view that uses the Student model. The StringLength attribute You can also specify data validation rules and validation error messages using attributes. The StringLength attribute sets the maximum length in the database and provides client side and server side validation for ASP.
You can also specify the minimum string length in this attribute, but the minimum value has no impact on the database schema. Suppose you want to ensure that users don't enter more than 50 characters for a name.
You can use the RegularExpression attribute to apply restrictions to the input. For example, the following code requires the first character to be upper case and the remaining characters to be alphabetical: The database model has now changed in a way that requires a change in the database schema.
You'll use migrations to update the schema without losing any data that you may have added to the database by using the application UI.
Save your changes and build the project. Then open the command window in the project folder and enter the following commands: This file contains code in the Up method that will update the database to match the current data model.
The database update command ran that code. The timestamp prefixed to the migrations file name is used by Entity Framework to order the migrations.
You can create multiple migrations before running the update-database command, and then all of the migrations are applied in the order in which they were created.1, 1-trichloroethane; trichloroethate 1/f, one over "f" noise where "f" is frequency 1D, one dimensional 1T-1C, 1 transistor/1 capacitor 1T-2C, 1 transistor/2 capacitor.
Other important terminology which I use in this article includes: benjaminpohle.com product, which often includes software, under development. benjaminpohle.com known as an end user, a user is a person who will actually work with the system/product being built. Class Diagram. The UML modeling tool lets you model the structure of system by modeling its classes, their attributes and operations in a UML class diagram.
WorldClim is a set of global climate layers (gridded climate data) with a spatial resolution of about 1 km benjaminpohle.com data can be used for mapping and spatial modeling.
Class Diagram. Model the structure of system by modeling its classes, their attributes and operations in a UML class diagram.
UML class diagram is a blueprint of the classes (code level) required to build a software system. Programmers implement a software system with the help of both the class diagram and the class specification.
Reza Rad is an Author, Trainer, Speaker and DW/BI Consultant. He has a BSc in Computer engineering; he has more than 15 years’ experience in databases, programming and development mostly on Microsoft technologies.