Skip to main content

Working with Database First: edmx in MVC

Database First approach creates all the model classes, properties and its context from the selecting database and then let the user access those classes for performing CRUD actions. User first have to create database and then follow this article to create an edmx file.
An edmx file is an XML file defines a model used to perform CRUD operations on database. This file can also be used with Entity Framework and contains some information to be used by EF designer. User can change this file to change EF designer and sometimes have to change in edmx file manually.
In previous article we have created a database EmpDb with single table, now we will create an edmx file for this database. By using the same MVC project (used in earlier articles) follow below steps:

  1. Right click on Models folder and Add New Item and then select ADO.NET Entity Data Model, name it whatever you want and click Add.
    Add New Item
  2. The next window is for choosing model contents whether from an existing database or an empty model. Because we have our existing database so select Generate from database and click on next.
    Generate from database

  3. You need to connect with your data connection, click on new connection and select Microsoft SQL Server from data source and then continue. After clicking on next button, it will ask for connection properties.
    new connection and select Microsoft SQL Server

  4. Enter server name or it may be selected by-default if you have any. It will load all the databases by clicking on drop-down for enter database name, select your database and click on OK. You can even test this connection whether it have problem or succeed.
Enter server name or it may be selected
  1. Now the third steps will open again with filled information like whole connection string and name in web.config to be saved. This entities name is changeable, leave it as is and next.
    name in web.config

  2. Next window will ask for entity framework version your project is using. It will detect all you entity framework versions and checked according to compatibility. Look out below image, it will disable V-6 and auto select V-5, so just next this step.
     entity framework version

  3. Choose database objects like tables, stored procedures etc. to be include in edmx file and click on next.
    Choose database objects like tables, stored procedures

  4. Your edmx file have been created as shown below.
 edmx file output

This will have all the tables in classes forms to be easily access by programmer and a constructor with the name of entities saved in web.config file. Now we can easily create our controllers and views as per the tables, we will continue in next article.


Popular posts from this blog

difference between structure and union in C Language

In c language article we will see the difference between union and structure. Both are the user define datatype in c language. See the table which is mentioned below: ASP.NET Video Tutorial Series Structure Union1.The keywordstruct is used to define a structure 1. The keyword union is used to define a union. 2. When a variable is associated with a structure, the compiler allocates the memory for each member. The size of structure is greater than or equal to the sum ofsizes of its members. The smaller members may end with unused slack bytes. 2. When a variable is associated with a union, thecompiler allocates thememory by considering the size of the largest memory. So, size of union is equal to the size of largest member. 3. Each member within a structure is assigned unique storage area of location. 3. Memory allocated is shared by individual members of union. 4. The address of each member will be in ascending order This indicates that memory for each member will start at different offset v…

Difference between Linear search and Binary Search in c language

SQL Video Channel : Download all SQL Video

Binary Search Linear Search Works only on sorted items. such as  1,2,3,4,5,6  etc
Works on sorted as well as unsorted items. 12,4,5,3,2,1 etc Very efficient if the items are sorted Very efficient if the items are less and present in the beginning of the list. such as Suppose your list items are : 12,3,4,5,1 and you want to search 12 number then you get beginning in the list. Works well with arrays and not on linked lists. Works with arrays and linked lists.
Number of comparisons are less More number of comparisons are required if the items are present in the later part of the array or its elements are more.

Memory representation of Linked List Data Structures in C Language

Memory representation of Linked List

             In memory the linked list is stored in scattered cells (locations).The memory for each node is allocated dynamically means as and when required. So the Linked List can increase as per the user wish and the size is not fixed, it can vary.

               Suppose first node of linked list is allocated with an address 1008. Its graphical representation looks like the figure shown below:

      Suppose next node is allocated at an address 506, so the list becomes,

  Suppose next node is allocated with an address with an address 10,s the list become,

The other way to represent the linked list is as shown below:

 In the above representation the data stored in the linked list is “INDIA”, the information part of each node contains one character. The external pointer root points to first node’s address 1005. The link part of the node containing information I contains 1007, the address of next node. The last node …