Simple GraphQL Tutorial In .NET Core Web API To Hit Ground Running

Run these commands in the command prompt after you get to your desired directory. This will create a solution:

dotnet new sln -n MOTUGraphQL

this will create a .NET core web project ,

dotnet new web -n MOTUGraphQL

this will add the project to the solution,

dotnet sln add MOTUGraphQL

Add these packages

Now open the solution you just created in Visual Studio (you can get a community edition for free)

Check if launchSettings.json file looks like this, if it is not then it won't start up in IIS server,

Contents of appsettings.js , this contains SQL server connection string and context name (developer edition is free to use)

{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft": "Warning",
"Microsoft.Hosting.Lifetime": "Information"
}
},
"AllowedHosts": "*",
"ConnectionStrings": {
"MotuContext": "Data Source=(local);Database=motu_characters;User ID=sa;Password=;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False"
}
}

Create a Faction.cs class which is the reflection of the table we are going to use.

Create a MotuContext.cs inherited from DbContext to create our context

Create a Query.cs class, which serves as our simple query resolver

public class Query {
//public IQueryable<Faction> GetFactions([Service] MotuContext context) =>
// context.Factions;
public List < Faction > GetFactions(string factionName, int ? baseFaction, int ? factionID,
[Service] MotuContext context) {
if (factionName == null && baseFaction == null && factionID == null) {
return context.Factions.ToList();
}
List < Faction > entries = new List < Faction > ();
if (factionID != null) {
entries.AddRange(context.Factions.Where(_ => _.FactionID == factionID).ToList());
}
if (baseFaction != null) {
entries.AddRange(context.Factions.Where(_ => _.BaseFaction == baseFaction).ToList());
}
if (factionName != null) {
entries.AddRange(context.Factions.Where(_ => _.FactionName.ToLower().Contains(factionName.ToLower())).ToList());
}
return entries;
}
}

Now we will go to Startup.cs where we will wire up these things

public class Startup {
public Startup(IConfiguration configuration) {
Configuration = configuration;
}
public IConfiguration Configuration {
get;
}
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services) {
services.AddControllers();
services.AddDbContext < MotuContext > (options => options.UseSqlServer(Configuration.GetConnectionString("MotuContext")));
services.AddRouting().AddGraphQLServer().AddQueryType < Query > ();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env) {
if (env.IsDevelopment()) {
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseEndpoints(endpoints => {
endpoints.MapGraphQL();
endpoints.MapControllers();
});
}
}
//if downloading source code does not work then run the commands in command line again and copy paste the //code again