There are various ways that you can query the Search Service in your SharePoint site:
1) Using the Search Web Service
2) Using the SharePoint Object Model
There are yet again two ways you can use the Search, using the Object Model:
i) KeywordQuery
ii) FullTextSqlQuery
I think it is a good option to use Object Model when you want to customize the Search (mostly in your WCM websites), and KeywordQuery comes in very handy!
Using KeywordQuery to search is pretty simple! (provided you have set up your Search properly)
KeywordQuery keywordQuery = new KeywordQuery(SPContext.Current.Site);
keywordQuery.ResultTypes = ResultType.RelevantResults | ResultType.SpecialTermResults;
keywordQuery.StartRow = 1;
keywordQuery.RowLimit = 5;
keywordQuery.SortList.Add("Rank", SortDirection.Descending);
keywordQuery.EnableStemming = true;
keywordQuery.TrimDuplicates = true;
keywordQuery.IgnoreAllNoiseQuery = true;
keywordQuery.HiddenConstraints = "scope:" + "\"" + SearchScope + "\"";
keywordQuery.QueryText = SearchText;
ResultTableCollection searchResults = keywordQuery.Execute();
As you can see above, I have combined the result type to be both RelevantResults and SpecialTermResults
Note: In WSS, only RelevantResults will work
One other thing to note in the above code is how we specify the scope using the HiddenConstraints
The search results are returned as a table collection. You can access the search tables as follows:
ResultTable relevantResultsTable = searchResults[ResultType.RelevantResults];
ResultTable specialTermResultsTable = searchResults[ResultType.SpecialTermResults];
If you want to load these into a DataSet with tables RelevantResults and SpecialTermResults respectively, then:
// Relevant Results table
DataTable relevantResults = new DataTable();
relevantResults.TableName = "RelevantResults";
// SpecialTerms Results table
DataTable specialTermResults = new DataTable();
specialTermResults.TableName = "SpecialTermResults";
// Search Results DataSet
DataSet resultSet = new DataSet();
// Relevant Results
relevantResults.Load(relevantResultsTable, LoadOption.OverwriteChanges);
resultSet.Tables.Add(relevantResults);
// SpecialTerms Results
resultSet.Tables.Add(specialTermResults);
specialTermResults.Load(specialResultsTable, LoadOption.OverwriteChanges);
You can now easily databind this DataSet
If you have worked with the Search Web Service, you will notice that the properties in KeywordQuery and the Search Query XML are similar
<?xml version="1.0" encoding="utf-8" ?>
<QueryPacket xmlns="urn:Microsoft.Search.Query" Revision="1000">
<Query domain="QDomain">
<SupportedFormats><Format>urn:Microsoft.Search.Response.Document.Document</Format></SupportedFormats>
<Context>
<QueryText language="en-US" type="STRING" > SCOPE:"All Sites"</QueryText>
</Context>
<SortByProperties><SortByProperty name="Rank" direction="Descending" order="1"/></SortByProperties>
<Range><StartAt>1</StartAt><Count>5</Count></Range>
<EnableStemming>true</EnableStemming>
<TrimDuplicates>true</TrimDuplicates>
<IgnoreAllNoiseQuery>true</IgnoreAllNoiseQuery>
<ImplicitAndBehavior>true</ImplicitAndBehavior>
<IncludeRelevanceResults>true</IncludeRelevanceResults>
<IncludeSpecialTermResults>true</IncludeSpecialTermResults>
<IncludeHighConfidenceResults>true</IncludeHighConfidenceResults>
</Query></QueryPacket>
(Above Search Query XML was generated using SharePoint Search Service Tool)