OK, now I give up. My challenge is to build a generic DAL using Entity Framework 6, Repository Pattern and N-Tier Solution Architecture.
Synopsis: Using this approach https://blog.magnusmontin.net/2013/05/30/generic-dal-using-entity-framework, I created my DAL and BLL. All good and well, Unittests completes without a hitch. Nice.
Challenge: I then created a Presentation Layer, which includes an Excel AddIn. But since the database used can be different from each client, the database ConnectionString needs to be changed from the client. OK, adding a app-config to the Excel-template project… doesn't work. No matter what I do, I get no data back from the database.
Now I need to remove the need for an app.config and instead just supply the ConnectionString from the Client, when initialising the BL.
I tried the suggestions from Entity Framework - Database First without config and How can l use Entity Framework without App.config, but I cannot seem the get it to fit nicely into my challenge. I did use some of the solutions mentioned in those, but since my DAL is using the Repository Pattern, I cannot quite get my limited head around how to implement the solutions mentioned...
What I have done: I added a DbConfiguration-class in the DataAccessLayer, which implements multiple constructors. (I cannot figure out HOW to hit the other constructors - only the parameterles constructor, but that's an issue for another question). My constructor for ythis classe looks like this:
private DefaultConfiguration()
{
SqlConnectionStringBuilder sqlBuilder = new SqlConnectionStringBuilder()
{
DataSource = database,
InitialCatalog = initialCatalog,
UserID = userId,
Password = password,
IntegratedSecurity = useTrustedConnection
};
// Initialize the EntityConnectionStringBuilder.
EntityConnectionStringBuilder entityBuilder = new EntityConnectionStringBuilder()
{
Provider = providerName,
// Set the provider-specific connection string.
ProviderConnectionString = sqlBuilder.ToString(),
// Set the Metadata location.
Metadata = @"res://*/CommonModel.csdl|res://*/CommonModel.ssdl|res://*/CommonModel.msl"
};
SetExecutionStrategy("System.Data.SqlClient", () => new DefaultExecutionStrategy(), database);
}
EntityConnection entityCon = new EntityConnection(entityBuilder.ToString());
//SetDefaultConnectionFactory(new SqlConnectionFactory(entityCon.ConnectionString));
//SetDefaultConnectionFactory(new SqlConnectionFactory(sqlBuilder.ToString()));
I just cant seem to figure out HOW to use my EntityConnection object in the initialisation of my DbConfiguration. Neither of the 2 last lines of code seems to be working properly.
In my DbContext, i changed the Constructor from
public CommonEntities()
: base("name=CommonEntities")
{
this.Configuration.LazyLoadingEnabled = false;
this.Configuration.ProxyCreationEnabled = false;
}
to
public CommonEntities(string ConnectionString)
: base(ConnectionString)
{
this.Configuration.LazyLoadingEnabled = false;
this.Configuration.ProxyCreationEnabled = false;
}
This though, only brings out the dreaded UnIntentionalCodeFirstException, and I am now stuck.
Question:
How do I get the ConnectionString from my PL all the way through to the DAL? I would try to create a non-parameterless Repository-constructor, which would accept a SQL-sonnectionstring as parameter, but how?
I know this is a huge question, but I have tried to give as much information I could without causing a SystemOutOfMemoryException and tried to boil my issue down to a single question - more questions WILL arise, later on, but for now this must suffice…
Hope some of you prodigies can give me a pointer or two…
