I need to create an Azure Function app using .Net 8 and EF Core where I can:
I've tried looking for tutorials or good working examples for the same but have come up empty handed so far. Any help here will be really appreciated.
EDIT: Adding error details.
I've tried the same approach as Vivek but I'm running into issues. For e.g., I am not able to get the data when I query using the dbContext. Here's my constructor:
public Function1(
ILogger<Function1> logger,
AppDbContext appDbContext)
{
_logger = logger;
_appDbContext = appDbContext;
try
{
var test = _appDbContext.Locations.First();
}
catch (Exception ex)
{
string message = ex.Message;
}
}
Checking the value of _dbContext.Locations shows the following error:
'((Microsoft.EntityFrameworkCore.Internal.InternalDbSet<Models.Location>)_appDbContext.Locations).Local' threw an exception of type 'System.InvalidOperationException'
The exception that I see in code is as following:
at Microsoft.Data.SqlClient.SqlBuffer.ThrowIfNull()
at Microsoft.Data.SqlClient.SqlBuffer.get_String()
at Microsoft.Data.SqlClient.SqlDataReader.GetString(Int32 i)
at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()
at System.Linq.Enumerable.TryGetSingle[TSource](IEnumerable`1 source, Boolean& found)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
at VTEst.Function1..ctor(ILogger`1 logger, AppDbContext appDbContext) in C:\Users\.....\Function1.cs:line 22
Finally, The output in the function console shows as following:
[2024-03-18T18:47:59.633Z] An exception occurred while iterating over the results of a query for context type 'VTest.AppDbContext'.
[2024-03-18T18:47:59.634Z] System.Data.SqlTypes.SqlNullValueException: Data is Null. This method or property cannot be called on Null values.
[2024-03-18T18:47:59.635Z] at Microsoft.Data.SqlClient.SqlBuffer.ThrowIfNull()
[2024-03-18T18:47:59.635Z] at Microsoft.Data.SqlClient.SqlBuffer.get_String()
[2024-03-18T18:47:59.636Z] at Microsoft.Data.SqlClient.SqlDataReader.GetString(Int32 i)
[2024-03-18T18:47:59.636Z] at lambda_method2(Closure, QueryContext, DbDataReader, ResultContext, SingleQueryResultCoordinator)
[2024-03-18T18:47:59.637Z] at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()
[2024-03-18T18:47:59.637Z] Result: An exception occurred while iterating over the results of a query for context type 'VTest.AppDbContext'.
[2024-03-18T18:47:59.638Z] System.Data.SqlTypes.SqlNullValueException: Data is Null. This method or property cannot be called on Null values.
[2024-03-18T18:47:59.639Z] at Microsoft.Data.SqlClient.SqlBuffer.ThrowIfNull()
[2024-03-18T18:47:59.639Z] at Microsoft.Data.SqlClient.SqlBuffer.get_String()
[2024-03-18T18:47:59.640Z] at Microsoft.Data.SqlClient.SqlDataReader.GetString(Int32 i)
[2024-03-18T18:47:59.640Z] at lambda_method2(Closure, QueryContext, DbDataReader, ResultContext, SingleQueryResultCoordinator)
[2024-03-18T18:47:59.641Z] at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()
Exception: System.Data.SqlTypes.SqlNullValueException: Data is Null. This method or property cannot be called on Null values.
[2024-03-18T18:47:59.641Z] at Microsoft.Data.SqlClient.SqlBuffer.ThrowIfNull()
[2024-03-18T18:47:59.642Z] at Microsoft.Data.SqlClient.SqlBuffer.get_String()
[2024-03-18T18:47:59.642Z] at Microsoft.Data.SqlClient.SqlDataReader.GetString(Int32 i)
[2024-03-18T18:47:59.643Z] at lambda_method2(Closure, QueryContext, DbDataReader, ResultContext, SingleQueryResultCoordinator)
[2024-03-18T18:47:59.644Z] at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext()
Stack: at Microsoft.Data.SqlClient.SqlBuffer.ThrowIfNull()
[2024-03-18T18:47:59.644Z] at Microsoft.Data.SqlClient.SqlBuffer.get_String()
[2024-03-18T18:47:59.645Z] at Microsoft.Data.SqlClient.SqlDataReader.GetString(Int32 i)
[2024-03-18T18:47:59.645Z] at lambda_method2(Closure, QueryContext, DbDataReader, ResultContext, SingleQueryResultCoordinator)
[2024-03-18T18:47:59.646Z] at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.Enumerator.MoveNext().
EDIT 2: Issue resolved
Vivek and Gert - Thank you very much for your help!
This worked for me. I have used Http Trigger function.
.csproj
:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>net8.0</TargetFramework>
<AzureFunctionsVersion>v4</AzureFunctionsVersion>
<OutputType>Exe</OutputType>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
<ItemGroup>
<FrameworkReference Include="Microsoft.AspNetCore.App" />
<PackageReference Include="Microsoft.Azure.Functions.Worker" Version="1.20.1" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.1.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore" Version="1.2.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="1.16.4" />
<PackageReference Include="Microsoft.ApplicationInsights.WorkerService" Version="2.21.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.ApplicationInsights" Version="1.1.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.3" />
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.3" />
</ItemGroup>
<ItemGroup>
<None Update="host.json">
<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</None>
<None Update="local.settings.json">
<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
<CopyToPublishDirectory>Never</CopyToPublishDirectory>
</None>
</ItemGroup>
<ItemGroup>
<Using Include="System.Threading.ExecutionContext" Alias="ExecutionContext" />
</ItemGroup>
</Project>
Program.cs
:
using FunctionApp14;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.EntityFrameworkCore;
using System;
var host = new HostBuilder()
.ConfigureFunctionsWebApplication()
.ConfigureServices(services =>
{
services.AddApplicationInsightsTelemetryWorkerService();
services.ConfigureFunctionsApplicationInsights();
services.AddDbContext<TodoContext>(options =>
options.UseSqlServer(Environment.GetEnvironmentVariable("SQL_Conn")));
})
.Build();
host.Run();
Function1.cs
:
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Logging;
using Microsoft.EntityFrameworkCore;
using System.Text.Json;
namespace FunctionApp14
{
public class Function1
{
private readonly ILogger<Function1> _logger;
private readonly TodoContext _context;
public Function1(ILogger<Function1> logger, TodoContext context)
{
_logger = logger;
_context = context;
}
[Function("Function1")]
public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req)
{
_logger.LogInformation("C# HTTP trigger function processed a request.");
string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
var input = JsonSerializer.Deserialize<TodoItem>(requestBody);
_context.TodoItems.Add(input);
await _context.SaveChangesAsync();
return new OkObjectResult($"Welcome to Azure Functions!\nData: {input}");
}
}
public class TodoItem
{
public int Id { get; set; }
public string Name { get; set; }
public bool IsComplete { get; set; }
}
public class TodoContext : DbContext
{
public TodoContext(DbContextOptions<TodoContext> options)
: base(options)
{
}
public DbSet<TodoItem> TodoItems { get; set; }
}
}
INPUT
:{
"Id": 1,
"Name": "Vivek",
"IsComplete": true
}
OUTPUT
:using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Logging;
using Microsoft.EntityFrameworkCore;
using System.Text.Json;
namespace FunctionApp14
{
public class Function1
{
private readonly ILogger<Function1> _logger;
private readonly TodoContext _context;
public Function1(ILogger<Function1> logger, TodoContext context)
{
_logger = logger;
_context = context;
}
[Function("Function1")]
public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req)
{
_logger.LogInformation("C# HTTP trigger function processed a request.");
var product = _context.TodoItems.ToList();
foreach (var item in product)
{
_logger.LogInformation($"id: {item.Id}\nname: {item.Name}\niscomplete:{item.IsComplete}");
}
return new OkObjectResult($"Welcome to Azure Functions!");
}
}
public class TodoItem
{
public int Id { get; set; }
public string Name { get; set; }
public bool IsComplete { get; set; }
}
public class TodoContext : DbContext
{
public TodoContext(DbContextOptions<TodoContext> options)
: base(options)
{
}
public DbSet<TodoItem> TodoItems { get; set; }
}
}
OUTPUT
: