Question

How can I check the results of LINQ query for a specific string value?

I have the following linq query:

IEnumerable<DataRow> rows = searchParamsTable.AsEnumerable()
                                        .Where(r => r.Field<String>("TABLE") == tableNumbers[i].ToString()
                                        && r.Field<String>("FIELD ") == fieldName[i]);

I want to see if the result of that query contains a string(passed in form a text box) “wildcardSearchString”.

Answer 1

var searchRows = 
        rows.Where(tr => tr.ItemArray
            .Any(ti => ti.ToString().IndexOf("wildcardSearchString", StringComparison.CurrentCultureIgnoreCase) > 0))

This will go through each of the rows that was returned, and see if “wildcardSearchString” is in the rows item string representation (ignoring case). Here’s the problem though, this won’t get you wildcard search support, so you’ll have to figure that one out yourself. You can try to use Regex, which would require a slight modification:

string searchPattern = "some*string".Replace("*", ".*");
var searchRows = 
        rows.Where(tr => tr.ItemArray
            .Any(ti => Regex.IsMatch(ti.ToString(), searchPattern)))

Hope that helps. Just be warned that if they decide to try supplying a Regex pattern than this might really mess up whatever they were searching for, so you just need to be careful of input.