How to fix “The ConnectionString property has not been initialized” in nopCommerce - entity-framework

Question

I'm trying to integrate nopCommerce into a third party system but am hitting a problem when I try to access any nopCommerce pages. Because I'm integrating with a third party system I've had to merge web.configs and copy all files over. I have a standalone install of nopCommerce aswell and that is running fine.
Any help would be greatly appreciated.
The error I am getting is as follows:
The ConnectionString property has not been initialized.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.InvalidOperationException: The ConnectionString property has not been initialized.
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack Trace:
[InvalidOperationException: The ConnectionString property has not been initialized.]
System.Data.SqlClient.SqlConnection.PermissionDemand() +5038498
System.Data.SqlClient.SqlConnectionFactory.PermissionDemand(DbConnection outerConnection) +20
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +126
System.Data.SqlClient.SqlConnection.Open() +125
System.Data.EntityClient.EntityConnection.OpenStoreConnectionIf(Boolean openCondition, DbConnection storeConnectionToOpen, DbConnection originalConnection, String exceptionCode, String attemptedOperation, Boolean& closeStoreConnectionOnFailure) +52
[EntityException: The underlying provider failed on Open.]
System.Data.EntityClient.EntityConnection.OpenStoreConnectionIf(Boolean openCondition, DbConnection storeConnectionToOpen, DbConnection originalConnection, String exceptionCode, String attemptedOperation, Boolean& closeStoreConnectionOnFailure) +161
System.Data.EntityClient.EntityConnection.Open() +98
System.Data.Objects.ObjectContext.EnsureConnection() +81
System.Data.Objects.ObjectQuery1.GetResults(Nullable1 forMergeOption) +46
System.Data.Objects.ObjectQuery1.System.Collections.Generic.IEnumerable<T>.GetEnumerator() +44
System.Linq.Enumerable.ToDictionary(IEnumerable1 source, Func2 keySelector, Func2 elementSelector, IEqualityComparer1 comparer) +151
System.Linq.Enumerable.ToDictionary(IEnumerable1 source, Func`2 keySelector) +90
NopSolutions.NopCommerce.BusinessLogic.Configuration.Settings.SettingManager.GetAllSettings() +542
NopSolutions.NopCommerce.BusinessLogic.Configuration.Settings.SettingManager.GetSettingByName(String name) +121
NopSolutions.NopCommerce.BusinessLogic.Configuration.Settings.SettingManager.GetSettingValue(String name) +49
NopSolutions.NopCommerce.BusinessLogic.Configuration.Settings.SettingManager.GetSettingValueBoolean(String name, Boolean defaultValue) +54
NopSolutions.NopCommerce.BusinessLogic.Configuration.Settings.SettingManager.GetSettingValueBoolean(String name) +41
NopSolutions.NopCommerce.BusinessLogic.CustomerManagement.CustomerManager.get_UsernamesEnabled() +45
NopSolutions.NopCommerce.Web.Administration.LoginPage.ApplyLocalization() +108
NopSolutions.NopCommerce.Web.Administration.LoginPage.Page_Load(Object sender, EventArgs e) +40
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
System.Web.UI.Control.OnLoad(EventArgs e) +91
NopSolutions.NopCommerce.Web.BaseNopAdministrationPage.OnLoad(EventArgs e) +44
System.Web.UI.Control.LoadRecursive() +74
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2207

Answer 1

You need to have a valid connection string.
After you pass the database installation phase (when you fill in the database settings) nop commerce is keeping the database information in a file that is not within the project, you can find it within the App_Data folder in the Presentation\Nop.Web\App_Data\ named Settings.txt, update it if you need and run the application again.

Answer 2

You need to have a valid connection string for the NopCommerce database in web.config, and you need to ensure that it gets read.
At Application_Start in global.asax NopCommerce reads in the connection string and injects it into the business logic DLL. If that doesn't happen, the data access layer (in the business logic DLL) won't be able to open a connection and you'll get the error you just posted. I suggest check web.config and global.asax; if both look good put a breakpoint in Application_Start.

Answer 3

The connection string is not held in the web.config file in nopcommerce... it is in the ConnectionStrings.config file. You might want to check for that file and copy it over if it is not there or put your connection string in there if the file is there and the string is not.