c# how to make a dynamic Context, to access different databases? - asp.net

Question

I am trying to access a different context with one variable. Please have a look at the code before:
...
private readonly ClientOneType _contextClientOne;
private readonly ClientTwoType _contextClientTwo;
public ExampleService()
{
_contextClientOne = new ClientOneType();
_contextClientTwo = new ClientTwoType();
}
public Stores[] GetStores(Store storeModel)
{
try
{
var _dynamicContext = null; //this throws an error because c# needs a type for runtime.
if (client == "OutBack")
_dynamicContext = _contextClientOne;
else if(client == "DollarGeneral")
_dynamicContext = _contextClientTwo;
var stores = (from s in _dynamicContext.Store //this is where the magic should take place
where s.StoreName == storeModel.StoreName
select p).ToArray();
return stores;
}
...
}
I get an error when running this because _dynamicContext can not be null so how can i create a variable that can be changed into different contexts?
The lazy solution would be to create different methods for each client, but that wouldn't be very effective as it will become unmaintainable.
I will really appreciate the help. Thank you in advance.

Answer 1

public interface IClientType
{
public Store Store { get; }
}
public class ClientOneType : IClientType
{
...
}
public class ClientTwoType : IClientType
{
...
}
public Stores[] GetStores(Store storeModel)
{
try
{
IClientType _dynamicContext = null;
...

Answer 2

Do ClientOneType and ClientTwoType both derrive from a base class that exposes the property named "Store" ?
I'm guessing they do not, and since they do not, there is no way to use the same variable to write the LINQ query you are writing because the compiler has to be able to determine what properties are available.
however, you could use IQueryable to dynamically build the query
IQueryable<Stores> storeQry=null;
if (client == "Walmart")
storeQry= _contextClientOne.Store.AsQueryable();
else if(client == "CHS")
storeQry= _contextClientTwo.Store.AsQueryable();
var stores = (from s in storeQry
where s.StoreName == storeModel.StoreName
select p).ToArray();