EF Core in the Console

  • Bare-bones Console Application
  • SQL Server Database
    • Store Data
    • Read Data

In This Presentation

  • Project Setup
  • Use JSON Data (to store in database)
  • Entity Framework Core
    • Entities
    • Database Context

Project Setup

  1. Create a new console application called "ConsoleApp" with a solution file called "EF Core Console.sln".
  2. Add a NuGet packages for Entity Framework:
    1. Microsoft.EntityFrameworkCore
    2. Microsoft.EntityFrameworkCore.SqlServer
  3. Add the School Catalog database to you database server
    1. SchoolCatalog.dacpac

Add JSON Files - courses.json

[
   {
      "courseId": "PROG-0101",
      "name": "Programming Fundamentals with OOP",
      "hours": 75,
      "credits": 3.0
   },
   {
      "courseId": "DATA-0150",
      "name": "Foundations of Database Design",
      "hours": 75,
      "credits": 3.0
   },
   {
      "courseId": "CORE-0103",
      "name": "Communications",
      "hours": 50,
      "credits": 2.0
   }
]

Add JSON Files - terms.json

[
    { "termId": 20203, "startDate": "2020-09-08", "endDate": "2020-12-18" },
    { "termId": 20211, "startDate": "2021-01-04", "endDate": "2021-04-23" },
    { "termId": 20212, "startDate": "2021-05-03", "endDate": "2021-07-30" },
    { "termId": 20213, "startDate": "2021-09-07", "endDate": "2012-12-17" },
    { "termId": 20221, "startDate": "2022-01-04", "endDate": "2022-04-22" },
    { "termId": 20222, "startDate": "2022-05-02", "endDate": "2022-07-29" },
    { "termId": 20223, "startDate": "2022-09-06", "endDate": "2022-12-16" }
]

Create Entity Classes - Term

public class Term
{
   public int TermId { get; set; }
   public DateTime StartDate { get; set; }
   public DateTime EndDate { get; set; }
   
   public override string ToString()
   {
         return $"{StartDate.ToShortDateString()}-{StartDate.ToShortDateString()}";
   }
}

Create Entity Classes - Course

public class Course
{
   public string CourseId { get; set; }
   public string Name { get; set; }
   public int Hours { get; set; }
   public double Credits { get; set; }

   public override string ToString()
   {
         return $"{CourseId} - {Name}";
   }
}

Create Entity Classes - Section

public class Section
{
   public int SectionId {get; set;}
   public int TermId { get; set; }
   public string CourseId { get; set; }
   public string Number { get; set; }
}

Add DAL Class

using Microsoft.EntityFrameworkCore;

public class SchoolCatalogContext : DbContext
{
   const string ConnectionString = 
      "Data Source=.;Initial Catalog=SchoolCatalog;Integrated Security=true;";
   
   public DbSet<Models.Course> Courses { get; set; }
   public DbSet<Models.Term> Terms { get; set; }
   
   protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
   {
         optionsBuilder.UseSqlServer(ConnectionString);
   }
}

Method to Read JSON Files

using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.Json;

IEnumerable<T> ReadData<T>(string fileName)
{
   var result = new List<T>();
   string jsonText = File.ReadAllText(fileName);
   var options = new JsonSerializerOptions
   {
         PropertyNamingPolicy = JsonNamingPolicy.CamelCase
   };
   result = JsonSerializer.Deserialize<List<T>>(jsonText, options);
   return result;
}

Code to Write to Database

Get the data from the JSON files

var courses = app.ReadData<Course>("courses.json");
var terms = app.ReadData<Term>("terms.json");

Write the data to the database (only if tables are empty)

using (var context = new Data.SchoolCatalogContext())
{
      if(!context.Courses.Any())
         context.Courses.AddRange(courses);
      if(!context.Terms.Any())
         context.Terms.AddRange(terms);
      context.SaveChanges();
}

Code to Read from Database

Read and display database contents

using (var context = new Data.SchoolCatalogContext())
{
      foreach(var item in context.Courses)
         Console.WriteLine(item);

      foreach(var item in context.Terms)
         Console.WriteLine(item);
}

The End