How to change database name in dbcontext connection string at runtime - asp.net-mvc

Question

My Asp.Net MVC application is setup as follows.
There are 4 projects in solution.
ge.Web
ge.BLL
ge.Core
ge.Entities
Controller in ge.Web initializes a repository object present in ge.Core
public class MapsController : Controller
{
private AssessmentRepository repAssessments = new AssessmentRepository("name=GEContext", schoolCode);
public ActionResult DisplaySearchResults()
{
.....
}
}
Assessments Repository
public class AssessmentRepository : Repository<Assessment>, IAssessmentRepository
{
public AssessmentRepository(string connString, string schoolCode)
:base(connString, schoolCode)
{ }
}
Repository
public class Repository<TEntity> : IRepository<TEntity> where TEntity:class
{
protected readonly GEContext context;
public Repository(string connString, string schoolCode) {
context = new GEContext(connString);
}
}
GEContext
public class GEContext : DbContext
{
public GEContext(string connString):base(connString)
{
this.Configuration.LazyLoadingEnabled = false;
Database.SetInitializer(new MySqlInitializer());
}
}
DbContext
public class DbContext : IDisposable, IObjectContextAdapter
{
public DbContext(string nameOrConnectionString);
}
Web.Config
<add name="GEContext" connectionString="server=localhost;port=4040;uid=root;pwd=xxx;database=ge" providerName="MySql.Data.MySqlClient" />
now i want to replace "database=ge" present in web.config with database=ge_[schoolCode]. at runtime How can i go about it?
UPDATE
My solution did not work. so i am stating the problem once again.
Web.Config
I have changed My config file to the following (previously GEContext was the only connection string)
<connectionStrings>
<add name="GEContext_sc001" connectionString="server=localhost;port=4040;uid=root;pwd=blabla;database=db_sc001" providerName="MySql.Data.MySqlClient" />
<add name="GEContext_sc002" connectionString="server=localhost;port=4040;uid=root;pwd=blabla;database=db" providerName="MySql.Data.MySqlClient" />
<appSettings>
<add key="SchoolCodes" value="sc001,sc002"/>
these are the allowed schoolCodes
Now when the user enters schoolcode at login screen, it is validated against the codes present in SchoolCodes key. and if yes, then it should try to connect to the connectionString for that particular connection. Now when my code comes to
UserManager.FindAsync
in Login function of AccountController, it crashes trying to find GEContext. Where is that set? and how can i change it?
I have changed the repository calling in controller as follows
private static string schoolCode = (string)System.Web.HttpContext.Current.Session["SchoolCode"];
private AssessmentRepository repAssessments = new AssessmentRepository("name=GEContext_" + schoolCode);
UPDATE-2
Following is present in ge.Web
IdentityConfig.cs
public class ApplicationUserManager : UserManager<ApplicationUser, int>
{
public ApplicationUserManager(IUserStore<ApplicationUser, int> store)
: base(store)
{
}
public static ApplicationUserManager Create(IdentityFactoryOptions<ApplicationUserManager> options, IOwinContext context)
{
var manager = new ApplicationUserManager(new UserStore<ApplicationUser, Role, int, UserLogin, UserRole, UserClaim>(context.Get<ApplicationDbContext>()));
...........
}
The following is present in ge.Core
ApplicationDbContext
public class ApplicationDbContext : IdentityDbContext<ApplicationUser, Role, int, UserLogin, UserRole, UserClaim>
{
public ApplicationDbContext(string connString)
: base(connString)
{
Database.SetInitializer(new MySqlInitializer());
}
public static ApplicationDbContext Create()
{
return new ApplicationDbContext("name=GEContext_");
}
}
How can i pass schoolCode from ge.web to ge.Core (answer should be straight forward but currently i cant get my head around it)
UPDATE-3
As told by itikhomi and taking help from this post I have changed my code as follows
in ApplicationDbContext class added the following
public static ApplicationDbContext Create(string scCode){
return new ApplicationDbContext("name=GEContext_" + scCode);
}
in AccountController Login
var appDbContext = ApplicationDbContext.Create(model.SchoolCode);
Request.GetOwinContext().Set<ApplicationDbContext>(appDbContext);
it still does not hit the correct database

Answer 1

You have two ways
1)
using System.Data.SqlClient;
public class Repository<TEntity> : IRepository<TEntity> where TEntity:class
{
protected readonly GEContext context;
public Repository(string connString, string schoolCode) {
context = new GEContext(connString);
var connection = new SqlConnectionStringBuilder(context.Database.Connection.ConnectionString);
connection.InitialCatalog = "YOUR_PREFIX_FROMSOMEWHERE"+schoolCode;
context.Database.Connection.ConnectionString = connection.ConnectionString;
}
}
2) if you wants to switch connection when it opened before use ChangeDatabase:
//open connection if it close
context.Database.Connection.ChangeDatabase("DATABASE-NAME");
NOTE: if use ChangeDatabase connection should be already opened
FOR UPDATE3:
You need to do somethink like this:
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
public ApplicationDbContext()
: base("DefaultConnection", throwIfV1Schema: false)
{
}
public ApplicationDbContext(string schoolCode)
: base(schoolCode)
{
var connection = new SqlConnectionStringBuilder(this.Database.Connection.ConnectionString);
connection.InitialCatalog = "YOUR_PREFIX_FROMSOMEWHERE" + schoolCode;
this.Database.Connection.ConnectionString = connection.ConnectionString;
}
public static ApplicationDbContext Create()
{
return new ApplicationDbContext();
}
}
in account controller:
public ApplicationSignInManager SignInManager
{
get
{
if (_signInManager == null)
{
var code = HttpContext.Request.Form.Get("SchoolCode");//Get from FORM\QueryString\Session whatever you wants
if (code != null)
{
HttpContext.GetOwinContext().Set<ApplicationSignInManager>(new ApplicationSignInManager(_userManager, HttpContext.GetOwinContext().Authentication));
}
_signInManager = HttpContext.GetOwinContext().Get<ApplicationSignInManager>();
}
return _signInManager;
}
private set
{
_signInManager = value;
}
}
public ApplicationUserManager UserManager
{
get
{
if (_userManager == null)
{
var code = HttpContext.Request.Form.Get("SchoolCode");//Get from FORM\QueryString\Session whatever you wants
if (code != null)
{
var appDbContext = new ApplicationDbContext(code);
HttpContext.GetOwinContext().Set<ApplicationDbContext>(appDbContext);
HttpContext.GetOwinContext().Set<ApplicationUserManager>(new ApplicationUserManager(new UserStore<ApplicationUser>(appDbContext))); //OR USE your specified create Method
}
_userManager = HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();
}
return _userManager;
}
private set
{
_userManager = value;
}
}
Your problem is in Store of UserManager is created before you change your OWIN context, in this case better to use DI like here

Answer 2

You can change the database for an open connection
context.Database.GetDbConnection().ChangeDatabase("");

Answer 3

I resolved it with the help of itikhomi..Posting the final code..
ApplicationDbContext
public static ApplicationDbContext Create()
{
return new ApplicationDbContext("name=GEContext");
}
AccountController
public ApplicationUserManager UserManager {
get
{
if (System.Web.HttpContext.Current.Session["SchoolCode"] == null)
return _userManager ?? HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();
else
{
var appDbContext = ApplicationDbContext.Create(System.Web.HttpContext.Current.Session["SchoolCode"].ToString());//new ApplicationDbContext("name=GEContext", System.Web.HttpContext.Current.Session["SchoolCode"].ToString());
HttpContext.GetOwinContext().Set<ApplicationDbContext>(appDbContext);
HttpContext.GetOwinContext().Set<ApplicationUserManager>(new ApplicationUserManager(new UserStore<ApplicationUser, Role, int, UserLogin, UserRole, UserClaim>(appDbContext)));
return HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();
}
}
private set
{
_userManager = value;
}
}