Linq with String Array Contains

Question

I have a string array of items & a list of database objects and I want to do a select query out of it

List<string> target_terms = new List<string> { "car", "mechanic" }

if (isNotExactPhrase)
{
    List<int> _tagIds = (from item in dbContext.Tags
                    where target_terms.Any(w => item.TagName.Contains(w))
                    select item.TagId).ToList();
}

I want all tags with names in the array

I have to use 2 options I want to check Tagname contains any of the keyword & If search is for exact phrase then I want to check any of the Tagname == any of the keyword

But for this query I am getting error

Local sequence cannot be used in LINQ to SQL implementations of query operators except the Contains operator.

How to solve this?

Your code does not even compile at the first line..

Binkan Salaryman
– Binkan Salaryman

2015-07-01 09:12:09 +00:00
Commented Jul 1, 2015 at 9:12 — Binkan Salaryman
– Binkan Salaryman, Commented Jul 1, 2015 at 9:12
Possible duplicate stackoverflow.com/questions/8164460/…

Nicolas C
– Nicolas C

2015-07-01 09:12:30 +00:00
Commented Jul 1, 2015 at 9:12 — Nicolas C
– Nicolas C, Commented Jul 1, 2015 at 9:12

Mukesh Kalgude · Accepted Answer · 2015-07-01 09:28:21Z

2

Try this query

var _tagIds = (from item in dbContext.Tags
                    where keywords.contains(item.TagName)
                    select item.TagId).ToList();

There's no direct equivalent, but there are some methods work similarly, depending on the pattern.

string.Contains("pattern") is equivalent to LIKE '%pattern%'

string.StartsWith("pattern") is equivalent to LIKE 'pattern%'

string.EndsWith("pattern") is equivalent to LIKE '%pattern'

edited Jul 1, 2015 at 9:28

answered Jul 1, 2015 at 9:13

Mukesh Kalgude

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4 Comments

Sebastian Over a year ago

This one worked but when i try to use another Linq Qury with this _tagIds its showing the same error

Mukesh Kalgude Over a year ago

Now check what is return.

Sebastian Over a year ago

How can i do the second case . Instead of using contains how can i check with == . Since if the user search for "car" and if there is a tag exists with word "carmel" that item will also be included

Yuriy A. Over a year ago

The Author tried to compare tags by substring. That is not the answer. (Author's Case: tag = "super_code", keyword = "er_co" ... your query will not return that as a result).

NinjaNye · Accepted Answer · 2015-07-28 16:25:39Z

1

After hitting this problem a multitude of times, I created a nuget package that solves this common issue.

Using NinjaNye.SearchExtensions you can do the following:

var _tagIds = dbContext.Tags.Search(t => t.TagName)
                            .Containing(keywords)
                            .Select(t => t.TagId)
                            .ToList();

If you needed to you could also search against multiple properties and return records where a match was found in either property.

var _tagIds = dbContext.Tags.Search(t => t.TagName, t => t.Description)
                            .Containing(keywords)
                            .Select(t => t.TagId)
                            .ToList();

Hope this helps

answered Jul 28, 2015 at 16:25

NinjaNye

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Comments

Microsoft DN · Accepted Answer · 2015-07-01 09:15:01Z

-1

Try replacing Any with contains

List<int> _tagIds = (from item in dbContext.Tags
                    where target_terms.Contains(w => item.TagName.Contains(w))
                    select item.TagId).ToList();

answered Jul 1, 2015 at 9:15

Microsoft DN

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1 Comment

Rohit Arora Over a year ago

I think Second contains should not be there if you are using target_terms.contains

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