CODEWITHSUNDEEP
c#.netlinq
Magnus Johansson
Magnus Johansson

Reputation: 28325

Usinq Linq to select items that is in a semi-comma separated string?

I have a string with semi-comma separated names:

string names = "Jane;Harry";

I also have a list of customer objects:

public class Customer
{
  public string FirstName { get; set; }
  public string LastName { get; set; }
}

List<Customer> customers = new List<Customer>();
customers.Add(new Customer(){FirstName="John", LastName="Doe"});
customers.Add(new Customer(){FirstName="Jane", LastName="Doe"});
customers.Add(new Customer(){FirstName="Harry", LastName="Potter"});

var query = from c in customers
            select c;

How do I create a query that returns only those customers that has a first name that is in the semi-comma separated list?

Something like the T-SQL SELECT FistName FROM customer WHERE FirstName IN (list) (sort of)

Upvotes: 6

Views: 15175

Answers (3)

Rinku Choudhary
Rinku Choudhary

Reputation: 2181

It Will Helps

string allid = "11,12,13,14,15,16";
string[] arrid = allid.Split(',');
var data = context.MyModels.Where(x => arrid.Contains(x.ProjectId.ToString()));

Upvotes: -1

dove
dove

Reputation: 20674

You can try this.

List firstnames = names.Split(';').ToList();

var query = from c in customers
            where firstnames.Contains(c.FirstName) 
            select c ;

Upvotes: 1

Jon Skeet
Jon Skeet

Reputation: 1500065

Well, you should really split the string up to start with - otherwise you'll get a match for "Jane" even if the list is "Janet;Harry".

You could do:

string[] validNames = names.Split(';');
var query = customers.Where(c => validNames.Contains(c.FirstName));

Another option is to use a HashSet, which will perform a lot better when the list is very large:

HashSet<string> validNames = new HashSet<string>(names.Split(';'));
var query = customers.Where(c => validNames.Contains(c.FirstName));

I've used dot notation here instead of a query expression because it's simpler when you're just applying a clause or two. As a query expression though, it would be:

var query = from c in customers
            where validNames.Contains(c.FirstName)
            select c;

Upvotes: 15

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