protected override void Init()
{
    if (Initialized)
        return;

    List<String> passedRelationNames = new List<string>();

    Connection.Open();
    try
    {
        DataTable dt = (Connection as SqlConnection).GetSchema("Tables");

        foreach (DataRow dr in dt.Rows)
        {
            string tableSchema = dr["TABLE_SCHEMA"].ToString();
            string tableType = dr["TABLE_TYPE"].ToString();
            string parentTableName = dr["TABLE_NAME"].ToString();          
            switch (tableType)
            {
                case "BASE TABLE":
                    if ((SupportedElementTypes & DbConnectionElementTypes.Table) == 0)
                        continue;
                    break;
                case "VIEW":
                    if ((SupportedElementTypes & DbConnectionElementTypes.View) == 0)
                        continue;
                    break;
                default:
                    continue;
            }

            // pass table
            SqlConnection newConnection = DbCommandSetDataProviderHelper.CloneConnection(Connection) as SqlConnection;
            SqlCommand cmd = new SqlCommand("Select * From \"" + (String.IsNullOrEmpty(tableSchema) ? parentTableName+"\"" : tableSchema + "\".\"" + parentTableName) + "\"", newConnection);
            Provider.AddCommand(cmd as IDbCommand, parentTableName);

            // pass relations
            string commandText = "sp_fkeys @pktable_name = '" + parentTableName + "'";
            if (!String.IsNullOrEmpty(tableSchema))
            {
                commandText+= ", @pktable_owner = '"+tableSchema+ "'";
            }
            cmd = new SqlCommand(commandText, Connection as SqlConnection);
            SqlDataReader reader = cmd.ExecuteReader();
            
            while (reader.Read())
            {
                string childColumnName = reader.GetSqlString(7).ToString();
                string parentColumnName = reader.GetSqlString(3).ToString();

                // combined primary key, add key field to last relation on stack
                if (reader.GetInt16(8) > 1)
                {
                    IDataProvider providerInterface = (Provider as IDataProvider);
                    DbCommandTableRelation lastRelation = providerInterface.Relations[providerInterface.Relations.Count - 1] as DbCommandTableRelation;
                    lastRelation.ChildColumnName += '\t' + childColumnName;
                    lastRelation.ParentColumnName += '\t' + parentColumnName;
                    continue;
                }
                string childTableName = reader.GetSqlString(6).ToString();
                string relName = reader.GetSqlString(2).ToString() + "2" + childTableName;
                int relationIndex = 1;
                string formatString = relName+"{0}";

                while (passedRelationNames.Contains(relName))
                {
                    relName = String.Format(formatString, relationIndex);
                    relationIndex++;
                }
                passedRelationNames.Add(relName);
                Provider.AddRelation(relName, parentTableName, childTableName, parentColumnName, childColumnName);                        
            }
            reader.Close();
        }
    }
    finally
    {
        Connection.Close();
        Initialized = true;
    }
}

protected override void OnTranslateFilterSyntax(object sender, TranslateFilterSyntaxEventArgs e)
{
    switch (e.ArgumentType)
    {
        case LlExpressionArgumentType.Function:
            switch (e.Name.ToString().ToUpper())
            {
                case "MID$":
                    if (e.ArgumentCount == 2)
                        e.Result = (String.Format("(SUBSTR({0},{1}))", e.Argument1.ToString(), e.Argument2.ToString() + "+1"));
                    else
                        e.Result = (String.Format("(SUBSTR({0},{1},{2}))", e.Argument1.ToString(), e.Argument2.ToString() + "+1", e.Argument3.ToString()));
                    break;
                case "LEFT$":
                    e.Result = (String.Format("(SUBSTR({0},0,{1}))", e.Argument1.ToString(), e.Argument2.ToString()));
                    break;
                case "RIGHT$":
                    e.Result = (String.Format("(SUBSTR({0},-{1},{1}))", e.Argument1.ToString(), e.Argument2.ToString()));
                    break;
                default:
                    e.Result = null;
                    break;
            }
            break;
        default:
            e.Result = null;
            break;
    }
}