Creare una connection string per EntityFramework a partire da una ConnectionString generica

(Scusate se il codice non è molto leggibile, ma lo spazio è quello che è)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data.EntityClient;
using System.Configuration;
using System.Data.Objects;
using System.IO;

namespace NameSpace.Commons

{

public class EntityConnStringBuilder

{

public static string GetNewAgeConnectionString(string dataModelName)

{

var esc = new EntitySqlConnectionStringBuilder(dataModelName, "ConnString");

return esc.GenerateConnectionString();

}

}

public sealed class EntitySqlConnectionStringBuilder

{

public string DataModelName { get; private set; }

public string ConnStringTagName { get; private set; }

public EntitySqlConnectionStringBuilder(string dataModelName, string connStringTagName)

{

DataModelName = dataModelName;

ConnStringTagName = connStringTagName;

}

public string GenerateConnectionString()

{

var connectString = GetSqlConnectionStringFromConfig();

var sqlBuilder = new SqlConnectionStringBuilder(connectString.ConnectionString);

string providerString = sqlBuilder.ToString();

var entityBuilder = new EntityConnectionStringBuilder();

entityBuilder.Provider = connectString.ProviderName;

entityBuilder.ProviderConnectionString = providerString;

entityBuilder.Metadata = GetMetadata();

return entityBuilder.ConnectionString;

}

private string GetMetadata()

{

var sb = new StringBuilder();

sb.Append(@"res://*/");

sb.Append(DataModelName);

sb.Append(@".csdl|");

sb.Append(@"res://*/");

sb.Append(DataModelName);

sb.Append(@".ssdl|");

sb.Append(@"res://*/");

sb.Append(DataModelName);

sb.Append(@".msl");

return sb.ToString();

}

private ConnectionStringSettings GetSqlConnectionStringFromConfig()

{

var conn = ConfigurationManager.ConnectionStrings[ConnStringTagName];

if (conn == null)

{

var strConn = ConfigurationManager.AppSettings[ConnStringTagName];

if (string.IsNullOrEmpty(strConn))

throw new ArgumentException("Nessuna Tag trovato tra le ConnectionString or AppSettings del file di configurazione per il connStringTagName in input :" + ConnStringTagName);

conn = new ConnectionStringSettings();

conn.ConnectionString = strConn;

conn.ProviderName = "System.Data.SqlClient";

}

return conn;

}

}

}