// Selects multiple records with an SQL statement.
private static Persons LoadClientSql(DbDataAccess dbDataAccess
    , DbColumns dataDefinition)
{
    Person retValue = null;

    StringBuilder builder = new StringBuilder(64);
    builder.AppendLine("select * from PersonTest");
    string sql = builder.ToString();

    DbColumns dataColumns = null;
    bool isColumnModifications = true;
    if (isColumnModifications)
    {
        // Create the list of included columns.
        // This list should include the database assigned columns.
        List<string> columnNames = new List<string>();
        foreach (DbColumn column in dataDefinition)
        {
            columnNames.Add(column.ColumnName);
        }

        // Create a Data Columns object with the included data definitions
        // and values from the data record.
        dataColumns = DbCommon.QueryColumns(columnNames, dataDefinition);
    }
    
    DbRequest dbRequest = new DbRequest()
    {
        ClientSql = sql
        Columns = dataColumns,
        QueryType = QueryType.LoadSQL.ToString(),
        TableName = "PersonTest",
    };
    DbResult dbResult = dbDataAccess.Execute(dbRequest);
    
    if (dbResult != null)
    {
        string sqlStatement = dbResult.ExecutedSql;
        if (dbResult.DbRecords != null && dbResult.DbRecords.Count > 0)
        {
            retValue = new Persons();
            foreach (DbValues dbValues in dbResult.DbRecords)
            {
                Person person = new Person();
                DbCommon.SetObjectValues(dbValues, retValue);
                retValue.Add(person);
            }
        }
        return retValue;
    }
}