CODEWITHSUNDEEP
entity-framework-4.1
Keith Barrows
Keith Barrows

Reputation: 25308

Changing the connection string in Entity Framework 4.1 POCO

I am using EF4.1, have upgraded my project, generated POCO classes to use DbContext now and have a fun time - except for changing connection strings on the fly. This projects imports CSV files then merges the data into 2 (identical) databases. One DB is our PROD server, the other is our DEV server. I realize the way I was doing the change (below) no longer works as I switched to POCO.

What I was doing:

internal static Model.RIVFeedsEntities GetFeedsDB()
{
    _serverName = "RivDB1";

    // Create the dbZach database entity...
    EntityConnectionStringBuilder entityBuilder = new EntityConnectionStringBuilder();
    string connString = String.Format(@"metadata=res://*/Model.Feeds.csdl|res://*/Model.Feeds.ssdl|res://*/Model.Feeds.msl;provider=System.Data.SqlClient;provider connection string='Data Source={0};Initial Catalog={1};Integrated Security=True;MultipleActiveResultSets=True'"
        , _serverName
        , _databaseName);
    entityBuilder.ConnectionString = connString;
    entityBuilder.Metadata = "res://*/";
    _sourceEntities = new Model.RIVFeedsEntities(entityBuilder.ConnectionString);
    _sourceEntities.CommandTimeout = 60;
    return _sourceEntities;
}

internal static Model.RIVFeedsEntities GetFeedsDBDev()
{
    _serverName = "DB1";

    // Create the dbZach database entity...
    EntityConnectionStringBuilder entityBuilder = new EntityConnectionStringBuilder();
    string connString = String.Format(@"metadata=res://*/Model.Feeds.csdl|res://*/Model.Feeds.ssdl|res://*/Model.Feeds.msl;provider=System.Data.SqlClient;provider connection string='Data Source={0};Initial Catalog={1};Integrated Security=True;MultipleActiveResultSets=True'"
        , _serverName
        , _databaseName);
    entityBuilder.ConnectionString = connString;
    entityBuilder.Metadata = "res://*/";
    _sourceEntities = new Model.RIVFeedsEntities(entityBuilder.ConnectionString);
    _sourceEntities.CommandTimeout = 60;
    return _sourceEntities;
}

As you can see all I really need to do is change the SERVER portion of the connection string.

How do you do this using the DbContext object? I can see the base allows sending in a name or conn string in the constructor but DbContext itself does not and I am not seeing anything exposed.

TIA

Upvotes: 4

Views: 8703

Answers (1)

Alexandre Brisebois
Alexandre Brisebois

Reputation: 6743

When you inherit from DbContext there are a few DbContext constructors from which you can override.

you may then choose from the different signature to find the one that suits you best.

in this forum http://social.msdn.microsoft.com/Forums/en/adodotnetentityframework/thread/2efc32f7-23ad-4fad-84cf-279badb394a5

they are using either an SqlConnection object or the ConnectionString.

I think this still applies to the RTW version of EF 4.1

Upvotes: 1

Related Questions