net core 1 (dnx 4.5.1) with enterpriselibrary 6 - setting up the connection string - connection-string

i ve big problems running enterprise library data access block with net core 1 (dnx 4.5.1)
How can i setup the default connection string for entlib
my appsettings.json
"ConnectionString": "Server=localhost\sqlexpress;Initial Catalog=blind;User Id=blind;Password=blind"
Here is my problem (no default connectionstring)
Database db = DatabaseFactory.CreateDatabase();
how can i pass the appsettings ConnectionString to the entlib databasefactory
any help would be greatly appreciated

I know it's an old question, but I have a similar setup (but using .NET Core 2.0) and it took me awhile to figure out how to set the default database connection without using the web.config to manage it.
What I did was include the default database and all of the connection strings in the appsettings.json and then in my Startup class I read the appsettings.json into an object that I defined to store the default db name and the connection strings and configure the default + named database using DatabaseFactory.SetDatabase.
DatabaseFactory.SetDatabases() Definition
public class DataConfiguration
{
public string DefaultDatabase { get; set; }
public List<ConnectionStringSettings> ConnectionStrings { get; set; }
}
public class Startup
{
public Startup(IConfiguration configuration)
{
//Get the Database Connections from appsettings.json
DataConfig = configuration.Get<DataConfiguration>();
var defaultDb = DataConfig.ConnectionStrings?.Find(c => c.Name == DataConfig.DefaultDatabase);
DatabaseFactory.SetDatabases(() => new SqlDatabase(defaultDb.ConnectionString), GetDatabase);
Configuration = configuration;
}
public Database GetDatabase(string name)
{
var dbInfo = DataConfig.ConnectionStrings.Find(c => c.Name == name);
if (dbInfo.ProviderName == "System.Data.SqlClient")
{
return new SqlDatabase(dbInfo.ConnectionString);
}
return new MySqlDatabase(dbInfo.ConnectionString);
}
}

Whenever there is documentation, I always suggest reading it as it is usually good. This is one of those examples, check out the "Getting Started with ASP.NET 5 and Entity Framework 6". There are several things that you need to do to ensure that you are correctly configured.
Setup your connection string and DI.
public class ApplicationDbContext : DbContext
{
public ApplicationDbContext(string nameOrConnectionString)
: base(nameOrConnectionString)
{
}
}
Also, notice the path in the configuration, it seems to differ from yours.
public void ConfigureServices(IServiceCollection services)
{
services.AddScoped((_) =>
new ApplicationDbContext(
Configuration["Data:DefaultConnection:ConnectionString"]));
// Configure remaining services
}

Related

Easily switching between connection strings in .NET Core

I've got a code base that uses EF Core and Dapper to perform actions on a database.
I want to set up a new copy of the site to develop some features and I want this site to connect to a new isolated copy of the database (dbConnectionDEBUG).
At the moment, I use the following setup:
startup.cs
...
services.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(
Configuration.GetConnectionString("dbConnectionMain")));
services.Configure<ConnectionStrings>(Configuration.GetSection("ConnectionStrings"));
...
I have a ConnectionStrings class which is being populated correctly via the DI in startup:
public class ConnectionStrings
{
public string dbConnectionMain { get; set; }
public string dbConnectionDEBUG { get; set; }
public ConnectionStrings()
{
this.dbConnectionMain = "";
this.dbConnectionDEBUG = "";
}
}
Then, throughout my controllers/services I have access to ConnectionStrings and 99% of the time I'm doing the following to make DB calls:
using (var conn = new SqlConnection(_connectionStrings.dbConnectionMain))
{
conn.Open();
...
This would amount to a lot of code changes if I were to want to switch over to the 'DEBUG' db.
How do I easily switch between the connection strings in my code depending on what version of the system I'm working on.
If I could somehow do this dynamically that'd be great. The obvious determining factor would be the URL the site is operating on.
Alternatively, (as a single change) do I just manually change the connection string at the source (e.g keystore/appsettings). I'm not keen on this as it leaves room for human error.
Update (2)
Based on what #Nkosi mentioned I am pursuing this path:
Have one connection string 'Id' (i.e. dbConnection) used throughout
Differentiate the connection string value within this based on the environment the app is running/deployed in
I have another question:
If I have the following...
"MYAPPNAME": {
"commandName": "Project",
"launchBrowser": true,
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Development"
},
"applicationUrl": "http://localhost:12345/;https://myapptestdomain.com/"
}
and:
WebHost.CreateDefaultBuilder(args)
.ConfigureAppConfiguration((context, config) =>
{
IHostingEnvironment env = context.HostingEnvironment;
config.AddJsonFile($"appsettings.{env.EnvironmentName.ToLower()}.json", optional: true);
})
.UseStartup<Startup>();
...will this automatically pick up my site is in the Development mode based on the applicationUrl values OR will I have to manually add ASPNETCORE_ENVIRONMENT with a value Development on the server I deploy the app to?
Additional: My app is running in an Azure App Service.
Update (3) - Mission Complete
Just to finalise this question (in case anyone needs to know this), I have the following setup based on recommendations made by #Nkosi.
Connection String - I have one connection string Id/name dbConnection which is used in all appSettings (see below)
App Settings
I have a default appSettings.json with dbConnection that looks at the live database
I have an additional appSettings.Playground.json file with dbConnection that looks at my testing database
Azure - App Service - On my playground development slot I have added an App Setting for ASPNETCORE_ENVIRONMENT with the value 'Playground'
In my Program.cs file I have:
config.AddJsonFile($"appsettings.json", optional: true,reloadOnChange: true);
and
config.AddJsonFile($"appsettings.{env.EnvironmentName.ToLower()}.json", optional: true,reloadOnChange: true);
Just to note, I do also initialise a Vault on Azure which stores all my Keys and Secrets for the Azure based apps. Locally User Secrets is used.
ASP.NET Core reads the environment variable ASPNETCORE_ENVIRONMENT at app startup and stores the value in IHostingEnvironment.EnvironmentName.
Since the environment is being loaded, then it should be available from the hosting environment via the builder context
WebHost.CreateDefaultBuilder(args)
.ConfigureAppConfiguration((context, config) => {
string environment = context.HostingEnvironment.EnvironmentName; //get current environment
//load config based on environment.
config.AddJsonFile($"appsettings.{environment}.json", optional: true);
//...
})
//...
Reference Use multiple environments in ASP.NET Core
For simple apps and to keep the connection strings away from my repository I use preprocessor statements plus PATH/System Variables and for release I provide a connection string within the settings.json.
#define USE_FEATURE_X
using System;
namespace MyNamespace {
internal static class StaticConnectionStringFactory {
public static string GetConnectionString() {
#if DEBUG && !USE_FEATURE_X
var connectionString = Environment.GetEnvironmentVariable("CNNSTR_SQL_XYZ", EnvironmentVariableTarget.User);
#elif DEBUG && USE_FEATURE_X
var connectionString = Environment.GetEnvironmentVariable("CNNSTR_SQL_ABC", EnvironmentVariableTarget.User);
#else
var connectionString = Environment.GetEnvironmentVariable("SqlConnectionString", EnvironmentVariableTarget.Process);
#endif
return connectionString;
}
}
}
I think if you add 2 connection for debug and main then you will have face some difficulty because more member working in you team. may be some own wrongly use release mode for code development.
you can try this webconfig method:
public class ConnectionStrings
{
public string dbConnection { get; set; }
public ConnectionStrings()
{
bool Ismain = bool.Parse(System.Configuration.ConfigurationManager.AppSettings["HasLive"]);
if (Ismain)
{
dbConnection = "";// get Main connectionstring
}
else
{
dbConnection = "";// get Debug connectionstring
}
}
}
web.config:
<connectionStrings>
<add name="dbConnectionMain" connectionString="" providerName="System.Data.SqlClient" />
<add name="dbConnectionDEBUG" connectionString="" roviderName="System.Data.SqlClient" />
</connectionStrings>
<appSettings>
<add key="HasLive" value="false"/>
</appSettings>
</connectionStrings>

Change SQL Server Connection String Dynamically inside an ASP.Net Core application

I open one database at the start, then need to open another database based on user selecting two values. The database selection has to be at run-time and will change every time.
Have tried to access the Connection String using the Connection String class and have tried other options like Singleton which I do not understand. I am running this on a local Windows 10 system running SQL Server Express. Am coding using Asp.Net Core 2.1
> ASP.Net Core v2.1
Building multi tenant, multi year application
Every client will have one SQL DATABASE per year
I hope to have a table with the following structure
COMPANY_CODE VARCHAR(3),
COMPANY_YEAR INT,
COMPANY_DBNAME VARCHAR(5)
Sample Data
COMPANY_CODE: AAD
COMPANY_YEAR: 19
COMPANY_DB: AAD19
COMPANY_CODE: AAD
COMPANY_YEAR: 18
COMPANY_DB: AAD18
COMPANY_CODE: AAD
COMPANY_YEAR: 17
COMPANY_DB: AAD17
So, every company will multiple rows - one for each financial year.
The COMPANY_DB column will store the DB name to open for that session.
Once the user is authenticated, I want to change the connection string to point to the database in the COMPANY_DB column of the selected row and then let the logged in user perform transactions.
I am unable to figure out how to change the connection string that is embedded in startup.cs.
Any tips on how to achieve this will be most appreciated.
I figured out that you are using one DbContext class for each database. See here for more information: docs.
Remove AddDbContext from Startup, remove OnConfiguring from DbContext and pass options to the constructor.
public class BloggingContext : DbContext
{
public BloggingContext(DbContextOptions<BloggingContext> options)
: base(options)
{ }
public DbSet<Blog> Blogs { get; set; }
}
Then, write service providing DbContext:
public interface IBlogContextProvider
{
BlogContext GetBlogContext(string connectionString);
}
public class BlogContextProvider : IBlogContextProvider
{
BlogContext GetBlogContext(string connectionString)
{
var optionsBuilder = new DbContextOptionsBuilder<BloggingContext>();
optionsBuilder.UseSqlServer(connectionString);
return new BlogContext(optionsBuilder);
}
}
Add service in your Startup.cs:
services.AddScoped<IBlogContextProvider, BlogContextProvider>();
Now you can use DI:
public class HomeController : Controller
{
private IBlogContextProvider _provider;
public HomeController(IBlogContextProvider provider)
{
_provider = provider;
}
public ActionResult Index()
{
using (var context = _provider.GetBlogContext(<your connection string>))
{
//your code here
}
return View();
}
}
EDIT: Of course, you can write ContextProvider as generic.

Database doesnt work on the server but does in my development environment

I am creating a mobile web app using MVC 4, I need to use a database to store details, the site then redirects to paypal, and on its return we use the paypal token to find the details in the database, this works fine on my local system, I have changed the (localdb) to .\SQLEXPRESS and that works ok, but when I put it onto my server, I get the error message "CREATE DATABASE permission denied in database 'master'"
I have sql server running, but I just cannot get it to connect.
The code generates the db with the following code
namespace PaypalTestWebApp.Models
{
public class StudentDetail
{
[Key]
public string token { get; set; }
public string studentDetails { get; set; }
public float depositAmount { get; set; }
}
public class StudentDetailsContext : DbContext
{
public DbSet<StudentDetail> studentDetails { get; set; }
}
}
and then I construct using the following in the page before I redirect
StudentDetailsContext db = new StudentDetailsContext();
StudentDetail sdb = new StudentDetail();
if (db.studentDetails.Find(paypal.token) == null)
{
log.Info("found paypal token");
sdb.token = checkoutResponse.Token;
sdb.studentDetails = CurrentUser.UserName;
sdb.depositAmount = float.Parse(CurrentUser.DepositAmount.ToString());
db.studentDetails.Add(sdb);
db.SaveChanges();
}
and in the return page I use the following :
StudentDetailsContext db = new StudentDetailsContext();
StudentDetail sdb = new StudentDetail();
sdb = db.studentDetails.Find(token);
CurrentUser.UserName = sdb.studentDetails;
CurrentUser.DepositAmount = sdb.depositAmount;
this all works fine on my machine, and creates the database in sql, but not on the server
my connection string is as follows :
<add name="StudentDetailsContext" connectionString="Data Source=.\SQLEXPRESS;Initial Catalog=StudentDetails;Integrated Security=True;Trusted_Connection=True" providerName="System.Data.SqlClient" />
Any help would be greatly appreciated
Thanks

Why is Entity Framework ignoring my connection string?

I have a connection string:
<add name="Gini" providerName="System.Data.SqlClient" connectionString="user id=user;Password=pa55;Data Source=server;Database=gini" />
I want EF to be able to control the creation of the database and updates through migrations so I'm letting it have complete control over the DB.
My contact class looks like the following:
public class GiniContext : DbContext
{
public DbSet<UserSession> UserSessions { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new UserSessionConfiguration());
}
public GiniContext() : base("Gini")
{
Database.Create();
}
}
I would expect this to create a database called "gini" on the server called "server" using the username and password as above but it's creating it on the (LocalDB)\v11.0 instance.
What am I doing wrong?
If you have two projects like a Class Library for Objects and a Web Application referencing it. You ll need to add the connection from app.config to the web.config in your web application.

Automatically switching connection string on database connection error

I'm dealing with a C# application with a EntityFramework backbone using a DbContext.
The application has two choices: connect to a remote SQL server express or connect to a local SQL compact 4.0 database in case the network connection is not available.
When my application starts, a thread is checking if a connection to the remote database is possible. Otherwise it automatically needs to switch the connection string and provider in order to connect to the local database.
So far I was trying to deal with this issue by modifying the connection string section in app.config and forcing the application to refresh the section, after saving the configuration. This approach is not the best since I need to have access rights to write into the app.config file.
Could you suggest a better approach?
Wrap the management of connection strings in a class, make that class a singleton, and use it to obtain the active connection string, like this:
public delegate void ConnectionChangedEventHandler(object sender, EventArgs e);
class ConnStringManager {
static public ConnStringManager Instance {get;private set;}
static {
Instance = new ConnStringManager();
}
public event ConnectionChangedEventHandler Changed;
private readonly string localConn;
private readonly string remoteConn;
public string ConnectionString {get; private set;}
private ConnStringManager() {
localConn = ... // Get local connection string from the config
remoteConn = ... // Get remote connection string from the config
TestAndSetConnectionString();
}
public void TestAndSetConnectionString() {
bool canUseRemote = true;
if (...) {
// Do some testing to see if remote DB is accessible
}
// Switch the connection string
var nextString = canUseRemote ? remoteConn : localConn;
bool changed = nextString != ConnectionString;
ConnectionString = nextString;
if (changed && Changed != null) {
Changed(this, EventArgs.Empty);
}
}
}
The DbContext constructor accepts either the name of the connection string, or the actual connection string you want to choose.
What you could do, is test your initial connection string - maybe with a quick ado connection or something simple, and then if it connects use it, otherwise connect using your other one.
Some pseudocode:
YourDbContext YourContext;
if (TestConnection())
{
YourContext = new YourDbContext("ConnectionString1");
}
else
{
YourContext = new YourDbContext("ConnectionString2");
}

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