DbConfiguration - problem to hold twice RRS feed

  • Question

  • Hi,

    I have two project type DLL , each one has Entity FrameWork 6 - using DbConfiguration

    something like this

    public class MyConfiguration : DbConfiguration { public MyConfiguration() { } }

    public class MyContextContext : DbContext 

    Each DLL when i run it only by himself (from another exe project) - works just fine.

    BUT - when i open new project (WPF) and have reference to both DLL - the code fail.

    I have read in the the internet this fact

    "Note: EF does not support having multiple configuration classes used in the same AppDomain"

    Please help me by give an idea how to solve this problem.

    Thank you


    Monday, June 5, 2017 8:31 AM

All replies

  • Hi Entity FrameWork6,

    Please special configuration class with namespace and assembly name, like this:

    [DbConfigurationType("MyNamespace.MyConfiguration, MyAssemblyFullyQualifiedName")]
    public class MyContextContext : DbContext

    if it does not works. please check the following workaround, Use the Context with constructor DbConnection .

    public class MyContextContext : DbContext {
         // MIgration parameterless constructor is managed in  MyMigrationsContextFactory 
        public MyContextContext(string connectionName) : base(connectionName) { } // no this
        public MyContextContext(DbConnection dbConnection, bool contextOwnsConnection)  // THIS ONE
            : base(dbConnection, contextOwnsConnection) {  }
    Then you could use a "DBConnection" connection for each provider. For SQL server

    public DbConnection GetSqlConn4DbName(string dataSource, string dbName) {
            var sqlConnStringBuilder = new SqlConnectionStringBuilder();
            sqlConnStringBuilder.DataSource = String.IsNullOrEmpty(dataSource) ? DefaultDataSource : dataSource;
            sqlConnStringBuilder.IntegratedSecurity = true;
            sqlConnStringBuilder.MultipleActiveResultSets = true;
            var sqlConnFact = new SqlConnectionFactory(sqlConnStringBuilder.ConnectionString);
            var sqlConn = sqlConnFact.CreateConnection(dbName);
            return sqlConn;

    Best regards,

    Cole Wu

    MSDN Community Support
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    Tuesday, June 6, 2017 5:59 AM