Week 09 - Day 1 - Intro to ORMS

[mdewey]

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title: ORM Safari! draft: true

We are taking a surprise trip to the Savannah for a safari to see all sorts of exotic animals. During our time there we want to keep track of all the animals we have seen. For this, we need to create a database, as well as a small console application to help record what we see.

Objectives

• Use an ORM to query against a database

Requirements

Explorer Mode

• [ ] Create a database called SafariVacation / safari_vacation

  • [ ] This will have 1 table called SeenAnimals / seen_animals that has the following columns
    • Id / id (int)
    • Species / species (string)
    • CountOfTimesSeen / count_of_times_seen (int)
    • LocationOfLastSeen / location_of_last_seen (string)
  • NOTE: This should be made all in the code (C#/Ruby), and not created in the pgcli.

• [ ] Create a small console application, and create the following queries using your languages ORM.

  • [ ] Display all animals the user has seen
  • [ ] Update the CountOfTimesSeen and LocationOfLastSeen for an animal
  • [ ] Display all animals seen in the Jungle
  • [ ] Remove all animals that I have seen in the Desert.
  • [ ] Add all the CountOfTimesSeen and get a total number of animals seen
  • [ ] Get the CountOfTimesSeen of lions, tigers and bears

Adventure Mode

• [ ] Add a new column called LastSeenTime (Ruby: last_seen_at), with a type of DateTime. This will require you to add and run a new migration.

Epic Mode

• [ ] Continue to make progress on your capstone project.

.NET Notes

Here are the interesting commands you will need for tonight's assignment

• To add Entity Framework to your project:

  dotnet add package Microsoft.EntityFrameworkCore.Design
  
  dotnet add package Npgsql.EntityFrameworkCore.PostgreSQL

  • To create your database:

    createdb <<DatabaseName>>

  • To create the DbContext

    
    dotnet ef dbcontext scaffold "server=localhost;database=<<DatabaseName>>" Npgsql.EntityFrameworkCore.PostgreSQL -c <<DatabaseName>>Context

- Add a migration:

dotnet ef migrations add AddBaordGameTable

- Update your database

dotnet ef database update

 - Documentation: [Dotnet EF CLI Docs](https://docs.microsoft.com/en-us/ef/core/miscellaneous/cli/dotnet)