Building a dynamic where clause for dynamic keywords or using IQueryable C# Linq

Question

I am trying to write a dynamic where clause using LINQ for returning all rows that contain any keyword supplied in an string array. The results do not come back as expected with what I have so far and looking at the SQL I can see the problem.

IQueryable<comments> query = _db.comments;

if (score != null)
    query = query.Where(x => x.score == score);
if (dateFrom != null)3
    query = query.Where(x => x.date_created >= dateFrom);
if (dateTo != null)
    query = query.Where(x => x.date_created <= dateTo);
if (keywords != null)
{
    //how to use OR for each in array?
    foreach (var keyword in keywords)
    {
        var keywordCondition = keyword;
        query = query.Where(x => x.text.Contains(keywordCondition));  
    }

}

WHERE ([Extent1].[score] = @p__linq__0) 
AND ([Extent1].[date_created] >= @p__linq__1) 
AND ([Extent1].[date_created] <= @p__linq__2) 
AND ([Extent1].[text] LIKE @p__linq__3 ESCAPE '~') 
AND ([Extent1].[text] LIKE @p__linq__4 ESCAPE '~')

--should be

WHERE ([Extent1].[score] = @p__linq__0) 
AND ([Extent1].[date_created] >= @p__linq__1) 
AND ([Extent1].[date_created] <= @p__linq__2) 
AND (([Extent1].[text] LIKE @p__linq__3 ESCAPE '~') 
    OR ([Extent1].[text] LIKE @p__linq__4 ESCAPE '~'))

I hope someone can help me as I've spent a couple of hours now searching for a solution.

Thanks in advance

Answer 1

As you have guessed, this is the part with the problem that you will need to change, because it will "AND" all of the clauses.

//how to use OR for each in array?
foreach (var keyword in keywords)
{
    var keywordCondition = keyword;
    query = query.Where(x => x.text.Contains(keywordCondition));  
}

I think you can do that by changing it to:

query = query.Where(x => keywords.Any(kw => x.text.Contains(kw));

Answer 2

You should really look into Dynamic LINQ queries ( explained very well here - http://weblogs.asp.net/scottgu/dynamic-linq-part-1-using-the-linq-dynamic-query-library)

You can specify your query like below -

.Where("Column1 = value1 OR Column2 = value2");