SharePoint - how to use sql query to retrieve or access SPList items using C# code

using (SPSite siteCollection = new SPSite(siteUrl))
{
    DataTable dt = new DataTable();
    DataSet Ds = new DataSet();
    Microsoft.Office.Server.Search.Query.FullTextSqlQuery query = new Microsoft.Office.Server.Search.Query.FullTextSqlQuery(siteCollection);
    //Select all the Meta data properties you need
    query.QueryText = "SELECT Title, Name, BlahBlah from scope() where \"scope\" =’<Scope Name>’";
    query.ResultTypes = Microsoft.Office.Server.Search.Query.ResultType.RelevantResults;
    query.RowLimit = Int32.MaxValue;
    query.TrimDuplicates = true;
    query.EnableStemming = false;
    query.IgnoreAllNoiseQuery = true;
    query.KeywordInclusion = Microsoft.Office.Server.Search.Query.KeywordInclusion.AllKeywords;
    query.Timeout = 0×2710;
    query.HighlightedSentenceCount = 3;
    query.SiteContext = new Uri(siteCollection.Url);
    query.AuthenticationType = Microsoft.Office.Server.Search.Query.QueryAuthenticationType.NtAuthenticatedQuery;
    try
    {
      Microsoft.Office.Server.Search.Query.ResultTableCollection queryResults = query.Execute();
      Microsoft.Office.Server.Search.Query.ResultTable queryResultsTable = queryResults[Microsoft.Office.Server.Search.Query.ResultType.RelevantResults];
      DataTable queryDataTable = new DataTable();
      queryDataTable.Load(queryResultsTable, LoadOption.OverwriteChanges);
        //You have all the required values in the data table
      dt = queryDataTable;
    }
    catch (Exception ex)
    {
        //Do Something
    }
}