C#: How can I select specific rows from the ResultsTable returned from a KeywordQuery?

Question

I am trying to perform a two-pass search against a Sharepoint list. In the first pass, I am using a KeywordQuery to search against the index of all the items. In the second pass, I am applying column value filters chosen by a user by building a select statement.

ResultTableCollection rtc = kwqry.Execute(); 
ResultTable rt = rtc[ResultType.RelevantResults]; 
dt = new DataTable(); 
//Load Data Table 
dt.Load(rt, LoadOption.OverwriteChanges); 
DataRow[] rows = dt.Select("ColumnName1 = 'foo' AND ColumnName2 = 'bar'"); 

Where the columns could be multi-value lookup columns in a Sharepoint list. The first pass is working properly and returning the right number of matches in a DataTable. However, when I try to apply the Select statement, I get the following error: Cannot perform '=' operation on System.String[] and System.String. Converting the columns to a string instead of a string array results in the same error, as does using the IN operator.

Am I building my select statement incorrectly? How could I run my second pass filter on my DataTable?

Answer 1

Have you tried with LINQ?

DataTable t1 = new DataTable();
var rows = from x in t1.AsEnumerable()
           where x.Field<string[]>("column1name").Contains("foo")
           select x;

You have to specify the field type in the Where clause...

Hope it helps.

Answer 2

Try using this, it will work :

DataRow[] rows = dt.Select("(ColumnName1 = 'foo' AND ColumnName2 = 'bar')");