Entity Framework, Code First and Full Text Search

Question

I realize that a lot of questions have been asked relating to full text search and Entity Framework, but I hope this question is a bit different.

I am using Entity F

Answer 1

The example here http://www.entityframework.info/Home/FullTextSearch is not complete solution. You will need to look into understand how the full text search works. Imagine you have a search field and the user types 2 words to hit search. The above code will throw an exception. You need to do pre-processing on the search phrase first to pass it to the query by using logical AND or OR.

for example your search phrase is "blah blah2" then you need to convert this into:

var searchTerm = @"\"blah\" AND/OR \"blah2\" "; 

Complete solution would be:

 value = Regex.Replace(value, @"\s+", " "); //replace multiplespaces
                    value = Regex.Replace(value, @"[^a-zA-Z0-9 -]", "").Trim();//remove non-alphanumeric characters and trim spaces

                    if (value.Any(Char.IsWhiteSpace))
                    {
                        value = PreProcessSearchKey(value);
                    }


 public static string PreProcessSearchKey(string searchKey)
    {
        var splitedKeyWords = searchKey.Split(null); //split from whitespaces

        // string[] addDoubleQuotes = new string[splitedKeyWords.Length];

        for (int j = 0; j < splitedKeyWords.Length; j++)
        {
            splitedKeyWords[j] = $"\"{splitedKeyWords[j]}\"";
        }

        return string.Join(" AND ", splitedKeyWords);
    }

this methods uses AND logic operator. You might pass that as an argument and use the method for both AND or OR operators.

You must escape none-alphanumeric characters otherwise it would throw exception when a user enters alpha numeric characters and you have no server site model level validation in place.