Entity Framework Core Demo - Complete Guide

This comprehensive demo shows the evolution from raw ADO.NET to Entity Framework Core, demonstrating Code-First approach with migrations and CRUD operations.

Overview: ADO.NET vs Entity Framework Core

Aspect	ADO.NET (Previous Demo)	Entity Framework Core
Database Operations	Manual SQL queries	LINQ expressions
Connection Management	Manual open/close	Automatic
Object Mapping	Manual mapping	Automatic ORM
Schema Management	Manual table creation	Code-First migrations
Type Safety	String-based queries	Strongly-typed

Step 1: Package Installation & Setup

Required NuGet Packages

1. Microsoft.EntityFrameworkCore 8.0.0          - Core EF functionality
2. Microsoft.EntityFrameworkCore.Design 8.0.0   - Design-time tools
3. Microsoft.EntityFrameworkCore.SqlServer 8.0.0 - SQL Server provider
4. Microsoft.EntityFrameworkCore.Tools 8.0.0    - Migration tools

Installation Commands

Install-Package Microsoft.EntityFrameworkCore -Version 8.0.0
Install-Package Microsoft.EntityFrameworkCore.Design -Version 8.0.0
Install-Package Microsoft.EntityFrameworkCore.SqlServer -Version 8.0.0
Install-Package Microsoft.EntityFrameworkCore.Tools -Version 8.0.0

Step 2: Entity Classes (POCOs) Analysis

Employee Entity

[Table("Employee")]  // Maps to 'Employee' table instead of 'Emp'
public class Emp
{
    [Column("No")]   // Maps to 'No' column
    [Key]            // Primary key designation
    public int No { get; set; }

    [Column("Name")]
    [StringLength(50)]  // Varchar(50) constraint
    public string Name { get; set; }

    [Column("Address")]
    [StringLength(50)]  // Varchar(50) constraint
    public string Address { get; set; }
}

Key Features:

Data Annotations: Control database schema generation
Table Mapping: [Table] specifies actual table name
Column Mapping: [Column] maps properties to specific columns
Constraints: [StringLength] creates varchar limitations
Primary Key: [Key] designates the primary key