My DbContext ctor looks like this:
public class FnordDbContext : DbContext
{
public FnordDbContext() : base("Fnord")
{
}
/* stuff */
}
And my mvc-mini-profiler bootstrapper looks like this:
var sqlConnectionFactory = new SqlConnectionFactory(ConfigurationManager.ConnectionStrings["Fnord"].ConnectionString);
var profiledConnectionFactory = new MvcMiniProfiler.Data.ProfiledDbConnectionFactory(sqlConnectionFactory);
Database.DefaultConnectionFactory = profiledConnectionFactory;
If I remove the connection string in my DbContext ctor, I get profiling as expected. But I don't want to have to name my connection string according to EF's convention. What do I need to change to make mvc-mini-profiler work with my DbContext use?
You can pass in the a ProfiledDbConnection explicitly to the ctor of your DbContext:
public class MyDbContext : DbContext {
public MyDbContext()
: base(GetProfiledConnection()) {
}
private static DbConnection GetProfiledConnection() {
var connectionString = ConfigurationManager.ConnectionStrings["name"].ConnectionString;
var connection = new SqlConnection(connectionString);
return ProfiledDbConnection.Get(connection);
}
}
Related
I am trying to figure out how to create a second DB context in EF7 RC1. In the past I could use a constructor with :base("connectionName") but that no longer seems an option since it says cannot convert string to System.IServiceProvider.
My second context code is as follows:
public class DecAppContext : DbContext
{
public DecAppContext()
// :base("DefaultConnection")
{
}
public DbSet<VignetteModels> VignetteModels { get; set; }
public DbSet<VignetteResult> Result { get; set; }
}
}
In my config.json I have the connection specified:
"Data": {
"DefaultConnection": {
"ConnectionString": "Server=(localdb)\\mssqllocaldb;Database=aspnet5-xxxxx...;Trusted_Connection=True;MultipleActiveResultSets=true"
}
}
In my configure services section of my startup I have both contexts added:
services.AddEntityFramework()
.AddSqlServer()
.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]))
.AddDbContext<DecAppContext>(options => options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));
The applicationDB context works fine since I can create a user and login without issue
However when I try to access the other context as in my controller via:
private DecAppContext db = new DecAppContext();
var vignette = db.VignetteModels.SingleOrDefault(v => v.CaseId == vid);
I get the error:
No database providers are configured. Configure a database provider by
overriding OnConfiguring in your DbContext class or in the
AddDbContext method when setting up services.
Any working examples in EF7 RC1 with multiple db contexts and accessing them would be much appreciated.
First of all I would recommend you the article from the wiki of EntityFramework on GitHub. The article describes many ways to define DbContext, which references to a section of appsettings.json. I personally prefer the way with the usage of [FromServices] attribute.
The code could be about the following:
First of all you defined appsettings.json with the following content
{
"Data": {
"ApplicationDbConnectionString": "Server=(localdb)\\mssqllocaldb;Database=ApplicationDb;Trusted_Connection=True;MultipleActiveResultSets=true",
"DecAppDbConnectionString": "Server=Server=(localdb)\\mssqllocaldb;Database=DecAppDb;Trusted_Connection=True;MultipleActiveResultSets=true"
}
}
where you define two connection strings.
Seconds you declare the classes DecAppContext and ApplicationDbContext which have DbContext as the base class. The simplest form will be just
public class ApplicationDbContext : DbContext
{
}
public class DecAppContext : DbContext
{
}
without any DbSet properties.
Third Step. You use Microsoft.Extensions.DependencyInjection to inject the database contexts. To do this you need just include in Startup.cs something like
public class Startup
{
// property for holding configuration
public IConfigurationRoot Configuration { get; set; }
public Startup(IHostingEnvironment env)
{
// Set up configuration sources.
var builder = new ConfigurationBuilder()
.AddJsonFile("appsettings.json")
.AddEnvironmentVariables();
// save the configuration in Configuration property
Configuration = builder.Build();
}
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
// Add framework services.
services.AddMvc()
.AddJsonOptions(options => {
options.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
});
services.AddEntityFramework()
.AddSqlServer()
.AddDbContext<ApplicationDbContext>(options => {
options.UseSqlServer(Configuration["Data:ApplicationDbConnectionString"]);
})
.AddDbContext<DecAppContext>(options => {
options.UseSqlServer(Configuration["Data:DecAppDbConnectionString"]);
});
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
...
}
}
Se create two DbContext (DecAppContext and ApplicationDbContext) using the configuration "Data:DecAppDbConnectionString" and "Data:ApplicationDbConnectionString".
Now we can just use the context in the controller. For example
[Route("api/[controller]")]
public class UsersController : Controller
{
[FromServices]
public ApplicationDbContext ApplicationDbContext { get; set; }
[FromServices]
public DecAppContext DecAppContext { get; set; }
[HttpGet]
public IEnumerable<object> Get() {
var returnObject = new List<dynamic>();
using (var cmd = ApplicationDbContext.Database.GetDbConnection().CreateCommand()) {
cmd.CommandText = "SELECT Id, FirstName FROM dbo.Users";
if (cmd.Connection.State != ConnectionState.Open)
cmd.Connection.Open();
var retObject = new List<dynamic>();
using (var dataReader = cmd.ExecuteReader())
{
while (dataReader.Read())
{
var dataRow = new ExpandoObject() as IDictionary<string, object>;
for (var iFiled = 0; iFiled < dataReader.FieldCount; iFiled++)
dataRow.Add(
dataReader.GetName(iFiled),
dataReader.IsDBNull(iFiled) ? null : dataReader[iFiled] // use null instead of {}
);
retObject.Add((ExpandoObject)dataRow);
}
}
return retObject;
}
}
}
or the same using async/await:
[Route("api/[controller]")]
public class UsersController : Controller
{
[FromServices]
public ApplicationDbContext ApplicationDbContext { get; set; }
[FromServices]
public DecAppContext DecAppContext { get; set; }
[HttpGet]
public async IEnumerable<object> Get() {
var returnObject = new List<dynamic>();
using (var cmd = ApplicationDbContext.Database.GetDbConnection().CreateCommand()) {
cmd.CommandText = "SELECT Id, FirstName FROM dbo.Users";
if (cmd.Connection.State != ConnectionState.Open)
cmd.Connection.Open();
var retObject = new List<dynamic>();
using (var dataReader = await cmd.ExecuteReaderAsync())
{
while (await dataReader.ReadAsync())
{
var dataRow = new ExpandoObject() as IDictionary<string, object>;
for (var iFiled = 0; iFiled < dataReader.FieldCount; iFiled++)
dataRow.Add(dataReader.GetName(iFiled), dataReader[iFiled]);
retObject.Add((ExpandoObject)dataRow);
}
}
return retObject;
}
}
}
One can just declare the property public ApplicationDbContext ApplicationDbContext { get; set; } with the attribute [FromServices] and ASP.NET initialize it from the context injected in ConfigureServices. In the same way one can use the second context DecAppContext whenever you need it.
The above code example will execute SELECT Id, FirstName From dbo.Users in the database context and return JSON data in the form [{"id":123, "firstName":"Oleg"},{"id":456, "firstName":"Xaxum"}]. The conversion of property names from Id and FirstName to id and firstName will be done automatically during serialization because of usage AddJsonOptions in ConfigureServices.
UPDATE: I have to reference the announcement. The next version of MVC (RC2) will require to change the above code to use [FromServices] as additional parameter (of method Get() for example) instead of usage public property [FromServices] public ApplicationDbContext ApplicationDbContext { get; set; }. One will need to remove the property ApplicationDbContext and to add additional parameter to Get() method: public async IEnumerable<object> Get([FromServices] ApplicationDbContext applicationDbContext) {...}. Such changes can be easy done. See here and example of the changes in the demo example of MVC:
[Route("api/[controller]")]
public class UsersController : Controller
{
[HttpGet]
public async IEnumerable<object> Get(
[FromServices] ApplicationDbContext applicationDbContext,
[FromServices] DecAppContext decAppContext)
{
var returnObject = new List<dynamic>();
// ... the same code as before, but using applicationDbContext
// and decAppContext parameters instead of ApplicationDbContext
// and DecAppContext properties
}
I try to learn repository.I created a class below,
public class Repository<T> where T : class
{
ObjectContext _context;
IObjectSet<T> _objectSet;
DBEntities db = new DBEntities ();
public void Delete(T entity)
{
_objectSet.DeleteObject(entity);
_context.SaveChanges();
}
}
}
I try to use void Delete in my controller below,
public ActionResult Index()
{
var something = new Repository<Department>();
something.Delete(.......); // What i must add to delete method ? How can i delete data from database ?
return View();
}
If i write int value to "something.Delete(2); it does not work, i do not know what to add here,how can i use repository ?
Try this article here:
The Repository Pattern Example in C#
MSDN ObjectContext.DeleteObject Method
I'm trying to set a property on an System.Web.Http.ApiController to a value of a resolved IServerPackageRepository. The controller runs in a HttpSelfHostServer and the DependencyResolver has been set to AutofacWebApiDependencyResolver. Here is the code from the Autofac.Module.Load method
...
builder.RegisterType<ServerPackageRepository>()
.As<IServerPackageRepository>()
.SingleInstance()
.WithParameter("path", this.StoragePath);
builder.RegisterApiControllers(Assembly.GetExecutingAssembly())
.PropertiesAutowired();
The ApiController controller itself has a property of type
public IServerPackageRepository Repository { get; set; }
but is never resolved.
I am trying to do it this way because ApiController won't take nothing but default constructors. Any suggestions on how to do this the correct way using Autofac?
If the ApiController is only using the default constructor is sounds like the dependency resolver is not being called and may not be registered with Web API correctly. Here is a working example of self-hosting with constructor injection.
The dependency (in this case a simple logger):
public interface ILogger
{
void Log(string text);
}
public class Logger : ILogger
{
public void Log(string text)
{
Debug.WriteLine(text);
}
}
A simple controller with a dependency on the logger:
public class ValuesController : ApiController
{
readonly ILogger _logger;
public ValuesController(ILogger logger)
{
_logger = logger;
}
// GET api/values
public IEnumerable<string> Get()
{
_logger.Log("GET api/values");
return new string[] { "value1", "value2" };
}
}
The console application:
class Program
{
static void Main(string[] args)
{
var configuration = new HttpSelfHostConfiguration("http://localhost:8080");
configuration.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
var builder = new ContainerBuilder();
// Register API controllers using assembly scanning.
builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
// Register API controller dependencies.
builder.Register<ILogger>(c => new Logger()).SingleInstance();
var container = builder.Build();
// Set the dependency resolver implementation.
var resolver = new AutofacWebApiDependencyResolver(container);
configuration.DependencyResolver = resolver;
// Open the HTTP server and listen for requests.
using (var server = new HttpSelfHostServer(configuration))
{
server.OpenAsync().Wait();
Console.WriteLine("Hosting at http://localhost:8080/{controller}");
Console.ReadLine();
}
}
}
Hit the controller action using:
http://localhost:8080/api/values
Please test this out and let me know if you have any problems.
Not sure if this is what you want but you can create your own base controller and inject the IServerPackageRepository into it.
public class MyApiController : ApiController {
public IServerPackageRepository ServerPackageRepository { get; set; }
public MyApiController(IServerPackageRepository serverPackageRepository) {
ServerPackageRepository = serverPackageRepository;
}
}
Then, use this as your base controller:
public class ProductsController : MyApiController {
public ProductsController(IServerPackageRepository serverPackageRepository)
: base(serverPackageRepository) {
}
public IEnumerable<Product> Get() {
ServerPackageRepository.DoWork();
//...
}
}
An alternative would be to directly wire your dependency to the property like so:
var repo = new ServerPackageRepository(path: this.StoragePath);
builder.RegisterInstance(repo)
.SingleInstance();
builder.RegisterApiControllers(Assembly.GetExecutingAssembly())
.WithProperty("Repository", repo)
.PropertiesAutowired();
While doing the following simple example, I found the following difficulties
As the title says, I am intending to use the Repository pattern while I am storing data in the Azure table storage.now I have couple of classes, Repository.cs, IRepository.cs, DataContext.cs and the Controller.
During my reading I found some info and been doing as follows.
IRepository.cs
public interface IRepository<T> where T: TableServiceEntity
{
T GetById(int Id);
IQueryable<T> GetAll();
}
and the DataContext.cs
public class DataContext<T>:TableServiceContext where T:TableServiceEntity
{
public DataContext(CloudStorageAccount storageaccount, StorageCredentials credentials)
: base(storageaccount.TableEndpoint.AbsoluteUri, credentials)
{
// _storageAccount = storageaccount;
var storageAccount = CloudStorageAccount.Parse(RoleEnvironment.GetConfigurationSettingValue(KEY_STORAGE));
storageAccount.CreateCloudTableClient().CreateTableIfNotExist(tableName);
}
public IQueryable<T> DeviceTable
{
get { return CreateQuery<T>(tableName); }
}
}
plus some part of the controller(I have already data in the table which I created before)
public class DeviceMeController : Controller
{
private IRepository<Entity>_repository;
public Controller() : this(new Repository<Entity>())
{
}
public Controller(IRepository<Entity> repository)
{
_repository = repository;
}
public ActionResult Index()
{
var List = _repository.GetAll();
return View(deviceList);
}
and the the Implementation of the interface Reposistory.cs, here is where I have an error and got lost somewhere
public class Repository<T>:IRepository<T> where T:TableServiceEntity
{
private DataContext<T> _serviceContext;
// here get tablename as pararameter;
// so the Enities call this function
public Repository()
{
// the same context for multiple tables ?
}
// perhaps it should take the table Name
public void Add(T item)
{
_serviceContext.AddObject(TableName,item);
_serviceContext.SaveChangesWithRetries();
}
public IQueryable<T> GetAll()
{
var results = from c in _serviceContext.Table
select c;
return results;
Error is about the null reference, the debugger shows the variable results is null?
In the end I need to know few things.
what should I do in the Repository.cs constructor? I believe the Datacontext.cs class has to be in a separate class ...
any Hint here
Hy,
first of all I presume you left out some code, because I don't see how you get your context in your repository. But supposing you do set it correctly, (injection?) taking into account the way you desinged your datacontext the repository doesn't need to know the table name because it is set in the following lines of code:
public IQueryable<T> DeviceTable
{
get { return CreateQuery<T>(Constants.DeviceTableName); }
}
So when you create a query based on the IQueryable DeviceTable, the table name is already set.
The thing is I don't see the need for your context class, especially as it can only bring over a single entity type (it is generic and based on an entity).
A basic layout of my Repository for Azure Table Storage is:
public abstract class CloudRepository<TEntity> : ICloudRepository<TEntity>
{
private TableServiceContext _tableServiceContext;
private string _tableName;
public string TableName
{
get { return _tableName ?? ( _tableName = typeof(TEntity).Name.Replace("Entity", string.Empty).ToLower()); }
}
public CloudStorageAccount StorageAccount
{
get
{
return CloudStorageAccount.Parse(RoleEnvironment.GetConfigurationSettingValue("StorageConnectionString"));
}
}
public CloudTableClient TableClient
{
get
{
CloudTableClient cloudTableClient = StorageAccount.CreateCloudTableClient();
cloudTableClient.CreateTableIfNotExist(TableName);
return cloudTableClient;
}
}
public TableServiceContext ServiceContext
{
get
{
return _tableServiceContext ?? (_tableServiceContext = TableClient.GetDataServiceContext());
}
}
public IEnumerable<TEntity> FindAll()
{
return ServiceContext.CreateQuery<TEntity>(TableName).ToList();
}
}
Hope this helps you.
I have a Singleton class that uses the thread-safe Singleton pattern from Jon Skeet as seen in the TekPub video. The class represents a cached list of reference data for dropdowns in an MVC 3 UI.
To get the list data the class calls a static method on a static class in my DAL.
Now I'm moving into testing an I want to implement an interface on my DAL class but obviously cannot because it is static and has only one static method so there's no interface to create. So I want to remove the static implementation so I can do the interface.
By doing so I can't call the method statically from the reference class and because the reference class is a singleton with a private ctor I can't inject the interface. How do I get around this? How do I get my interface into the reference class so that I can have DI and I can successfully test it with a mock?
Here is my DAL class in current form
public static class ListItemRepository {
public static List<ReferenceDTO> All() {
List<ReferenceDTO> fullList;
... /// populate list
return fullList;
}
}
This is what I want it to look like
public interface IListItemRepository {
List<ReferenceDTO> All();
}
public class ListItemRepository : IListItemRepository {
public List<ReferenceDTO> All() {
List<ReferenceDTO> fullList;
... /// populate list
return fullList;
}
}
And here is my singleton reference class, the call to the static method is in the CheckRefresh call
public sealed class ListItemReference {
private static readonly Lazy<ListItemReference> instance =
new Lazy<ListItemReference>(() => new ListItemReference(), true);
private const int RefreshInterval = 60;
private List<ReferenceDTO> cache;
private DateTime nextRefreshDate = DateTime.MinValue;
public static ListItemReference Instance {
get { return instance.Value; }
}
public List<SelectListDTO> SelectList {
get {
var lst = GetSelectList();
lst = ReferenceHelper.AddDefaultItemToList(lst);
return lst;
}
}
private ListItemReference() { }
public ReferenceDTO GetByID(int id) {
CheckRefresh();
return cache.Find(item => item.ID == id);
}
public void InvalidateCache() {
nextRefreshDate = DateTime.MinValue;
}
private List<SelectListDTO> GetSelectList() {
CheckRefresh();
var lst = new List<SelectListDTO>(cache.Count + 1);
cache.ForEach(item => lst.Add(new SelectListDTO { ID = item.ID, Name = item.Name }));
return lst;
}
private void CheckRefresh() {
if (DateTime.Now <= nextRefreshDate) return;
cache = ListItemRepository.All(); // Here is the call to the static class method
nextRefreshDate = DateTime.Now.AddSeconds(RefreshInterval);
}
}
}
You can use the singleton based on instance(not based on static), for which you can declare interface like this.
public interface IListItemRepository
{
List<ReferenceDTO> All();
}
public class ListItemRepository : IListItemRepository
{
static IListItemRepository _current = new ListItemRepository();
public static IListItemRepository Current
{
get { return _current; }
}
public static void SetCurrent(IListItemRepository listItemRepository)
{
_current = listItemRepository;
}
public List<ReferenceDTO> All()
{
.....
}
}
Now, you can mock IListItemRepository to test.
public void Test()
{
//arrange
//If Moq framework is used,
var expected = new List<ReferneceDTO>{new ReferneceDTO()};
var mock = new Mock<IListItemRepository>();
mock.Setup(x=>x.All()).Returns(expected);
ListItemRepository.SetCurrent(mock.Object);
//act
var result = ListItemRepository.Current.All();
//Assert
Assert.IsSame(expected, result);
}
Which DI framework are you using? Depending on your answer, IOC container should be able to handle single-instancing so that you don't have to implement your own singleton pattern in the caching class. In your code you would treat everything as instanced classes, but in your DI framework mappings you would be able to specify that only one instance of the cache class should ever be created.
One way to test it would be if you refactor your ListItemReference by adding extra property:
public sealed class ListItemReference {
...
public Func<List<ReferenceDTO>> References = () => ListItemRepository.All();
...
private void CheckRefresh() {
if (DateTime.Now <= nextRefreshDate) return;
cache = References();
nextRefreshDate = DateTime.Now.AddSeconds(RefreshInterval);
}
}
And then in your test you could do:
ListItemReference listReferences = new ListItemReference();
listReferences.References = () => new List<ReferenceDTO>(); //here you can return any mock data
Of course it's just temporary solution and I would recommend getting rid of statics by using IoC/DI.