feat: Implement database schema, relationships and models for survey application

- Designed an ERD (Entity-Relationship Diagram) for the survey system.
- Defined entities: User, Survey, Question, Choice, Response, and Answer.
- Established relationships:
  - Users can author multiple surveys.
  - Surveys contain multiple questions.
  - Questions have multiple choices.
  - Surveys can have multiple responses from participants.
  - Responses are linked to answers, questions, and choices.
- Ensured compliance with best practices for relational database design.
Note : no migration yet

survey-beta.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.11.35312.102
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "survey-beta", "survey-beta\survey-beta.csproj", "{7A5087A4-5EFE-49C8-AD7A-A2AC9F815C32}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{7A5087A4-5EFE-49C8-AD7A-A2AC9F815C32}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{7A5087A4-5EFE-49C8-AD7A-A2AC9F815C32}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{7A5087A4-5EFE-49C8-AD7A-A2AC9F815C32}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{7A5087A4-5EFE-49C8-AD7A-A2AC9F815C32}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {AD3F914F-11E0-46E6-A86F-6C7743255DC4}
+	EndGlobalSection
+EndGlobal

survey-beta/DataBaseContext/AppDbContext.cs

@@ -0,0 +1,56 @@
+using Microsoft.EntityFrameworkCore;
+using survey_beta.Models;
+namespace survey_beta.DataBaseContext
+{
+    public class AppDbContext : DbContext
+    {
+        public DbSet<User> Users { get; set; }
+        public DbSet<Survey> Surveys { get; set; }
+        public DbSet<Question> Questions { get; set; }
+        public DbSet<Choice> Choices { get; set; }
+        public DbSet<Response> Responses { get; set; }
+        public DbSet<Answer> Answers { get; set; }
+
+        public AppDbContext(DbContextOptions<AppDbContext> options) : base(options)
+        {
+        }
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            modelBuilder.Entity<Survey>()
+                .HasOne(s => s.Author)
+                .WithMany(u => u.Surveys)
+                .HasForeignKey(s => s.AuthorId);
+
+            modelBuilder.Entity<Question>()
+                .HasOne(q => q.Survey)
+                .WithMany(s => s.Questions)
+                .HasForeignKey(q => q.SurveyId);
+
+            modelBuilder.Entity<Choice>()
+                .HasOne(c => c.Question)
+                .WithMany(q => q.Choices)
+                .HasForeignKey(c => c.QuestionId);
+
+            modelBuilder.Entity<Response>()
+                .HasOne(r => r.Survey)
+                .WithMany(s => s.Responses)
+                .HasForeignKey(r => r.SurveyId);
+
+            modelBuilder.Entity<Answer>()
+                .HasOne(a => a.Response)
+                .WithMany(r => r.Answers)
+                .HasForeignKey(a => a.ResponseId);
+
+            modelBuilder.Entity<Answer>()
+                .HasOne(a => a.Question)
+                .WithMany()
+                .HasForeignKey(a => a.QuestionId);
+
+            modelBuilder.Entity<Answer>()
+                .HasOne(a => a.Choice)
+                .WithMany()
+                .HasForeignKey(a => a.ChoiceId);
+        }
+    }
+}
+

survey-beta/Models/Answer.cs

@@ -0,0 +1,13 @@
+namespace survey_beta.Models
+{
+    public class Answer
+    {
+        public string Id { get; set; }
+        public string ResponseId { get; set; }
+        public Response Response { get; set; }
+        public string QuestionId { get; set; }
+        public Question Question { get; set; }
+        public string ChoiceId { get; set; }
+        public Choice Choice { get; set; }
+    }
+}

survey-beta/Models/Choice.cs

@@ -0,0 +1,11 @@
+namespace survey_beta.Models
+{
+    public class Choice
+    {
+        public string Id { get; set; }
+        public string Letter { get; set; }
+        public string Content { get; set; }
+        public string QuestionId { get; set; }
+        public Question Question { get; set; }
+    }
+}

survey-beta/Models/Question.cs

@@ -0,0 +1,11 @@
+namespace survey_beta.Models
+{
+    public class Question
+    {
+        public string Id { get; set; }
+        public string Content { get; set; }
+        public string SurveyId { get; set; }
+        public Survey Survey { get; set; }
+        public ICollection<Choice> Choices { get; set; }
+    }
+}

survey-beta/Models/Response.cs

@@ -0,0 +1,11 @@
+namespace survey_beta.Models
+{
+    public class Response
+    {
+        public string Id { get; set; }
+        public string IpAddress { get; set; }
+        public string SurveyId { get; set; }
+        public Survey Survey { get; set; }
+        public ICollection<Answer> Answers { get; set; }
+    }
+}

survey-beta/Models/Survey.cs

@@ -0,0 +1,16 @@
+namespace survey_beta.Models
+{
+    public class Survey
+    { 
+        public string Id { get; set; }
+        public string Title { get; set; }
+        public string Description { get; set; }
+        public string Category { get; set; }
+        public DateTime ExpirationDate { get; set; }
+        public bool IsPublished { get; set; }
+        public string AuthorId { get; set; }
+        public User Author { get; set; }
+        public ICollection<Question> Questions { get; set; }
+        public ICollection<Response> Responses { get; set; }
+    }
+}

survey-beta/Models/User.cs

@@ -0,0 +1,13 @@
+namespace survey_beta.Models
+{
+    public class User
+    {
+        public string? Id { get; set; }
+        public string? Username { get; set; }
+        public string? Fullname { get; set; }
+        public string? Email { get; set; }
+        public string? PasswordHash { get; set; }
+        public ICollection<Survey> Surveys { get; set; } = new List<Survey>();
+
+    }
+}

survey-beta/Program.cs

@@ -0,0 +1,23 @@
+using Microsoft.EntityFrameworkCore;
+using survey_beta.DataBaseContext;
+
+var builder = WebApplication.CreateBuilder(args);
+
+// Add services to the container
+builder.Services.AddDbContext<AppDbContext>(options =>
+    options.UseNpgsql(builder.Configuration.GetConnectionString("DefaultConnection")));
+
+builder.Services.AddControllers(); 
+builder.Services.AddEndpointsApiExplorer(); 
+
+var app = builder.Build();
+
+// Configure the HTTP request pipeline.
+
+app.UseHttpsRedirection();
+
+app.UseAuthorization();
+
+app.MapControllers();
+
+app.Run();

survey-beta/Properties/launchSettings.json

@@ -0,0 +1,41 @@
+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:5388",
+      "sslPort": 44392
+    }
+  },
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "weatherforecast",
+      "applicationUrl": "http://localhost:5036",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "weatherforecast",
+      "applicationUrl": "https://localhost:7002;http://localhost:5036",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "launchUrl": "weatherforecast",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

survey-beta/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

survey-beta/appsettings.json

@@ -0,0 +1,12 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*",
+  "ConnectionStrings": {
+    "DefaultConnection": "Host=localhost;Database=SurveyDB;Username=postgre;Password=MAJEDali645"
+  }
+}

survey-beta/survey-beta.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <RootNamespace>survey_beta</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.1" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="9.0.1">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.3" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Folder Include="Controllers\" />
+    <Folder Include="Services\" />
+  </ItemGroup>
+
+</Project>

survey-beta/survey-beta.csproj.user

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="Current" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <ActiveDebugProfile>https</ActiveDebugProfile>
+  </PropertyGroup>
+</Project>

survey-beta/survey-beta.http

@@ -0,0 +1,6 @@
+@survey_beta_HostAddress = http://localhost:5036
+
+GET {{survey_beta_HostAddress}}/
+Accept: application/json
+
+###