how to use CSOM and search API to query a document library

Question

Below is my code to search for a keyword

using ( ClientContext clientContext = new ClientContext ( new Uri ( "https://company.sharepoint.com/sites/records/" ) ) )
{
    clientContext.Credentials = Credentials;
    KeywordQuery keywordQuery = new KeywordQuery ( clientContext );
    keywordQuery.QueryText = "SharePoint";
    keywordQuery.TrimDuplicates = false;

    // additional properties for keywordQuery which limit the results to particulat document library

    SearchExecutor searchExecutor = new SearchExecutor ( clientContext );
    ClientResult<ResultTableCollection> results = searchExecutor.ExecuteQuery ( keywordQuery );
    clientContext.ExecuteQuery ( );

    ResultTable resultTable = results.Value.FirstOrDefault ( );

}

I could barely find any working examples over the internet which restricts the results to only one particular document library.

Answer 1

I can think if two easy ways to do it.

1. Create a result source: Configure the below query to result source

{searchTerms} (ListID:{library guid here} AND ContentClass:STS_ListItem )

Now set the KeyWordQuery to use the result source.

keywordQuery.SourceId="id of result source";

2. Just add the result source query directly into the query text.

keywordQuery.QueryText="(ListID:{library guid here} AND ContentClass:STS_ListItem ) SharePoint";