How to do SQL Like % in Linq?

Question

Hello All,

I have a procedure in SQL that I am trying to turn into Linq:

SELECT O.Id, O.Name as Organization
FROM Organizations O
JOIN OrganizationsHierarchy OH ON O.Id=OH.OrganizationsId
where OH.Hierarchy like '%/12/%'

The line I am most concerned with is:

where OH.Hierarchy like '%/12/%'

I have a column that stores the hierarchy like /1/3/12/ for example so I just use %/12/% to search for it.

My question is, what is the Linq or .NET equivalent to using the percent sign?

Much appreciated,

-Matt

Answer 1

.Where(oh => oh.Hierarchy.Contains("/12/"))

you can also use .StartsWith() or .EndsWidth()

Answer 2

I'm assuming you're using Linq-to-SQL* (see note below). If so, use string.Contains, string.StartsWith, and string.EndsWith to generate SQL that use the SQL LIKE operator.

from o in dc.Organization
join oh in dc.OrganizationsHierarchy on o.Id equals oh.OrganizationsId
where oh.Hierarchy.Contains(@"/12/")
select new { o.Id, o.Name }

or

from o in dc.Organization
where o.OrganizationsHierarchy.Hierarchy.Contains(@"/12/")
select new { o.Id, o.Name }

Note: * = if you are using the ADO.Net Entity Framework (EF / L2E) in .net 3.5, be aware that it will not do the same translation as Linq-to-SQL. Although L2S does a proper translation, L2E v1 (3.5) will translate into a t-sql expression that will force a full table scan on the table you're querying unless there is another better discriminator in your where clause or join filters.
Update: This is fixed in EF/L2E v4 (.net 4.0), so it will generate a SQL LIKE just like L2S does.

Answer 3

If you are using VB.NET, then the answer would be "*". Here is what your where clause would look like...

Where OH.Hierarchy Like '*/12/*'

Note: "*" Matches zero or more characters. Here is the msdn article for the Like operator.

Answer 4

Use this

from c in dc.Organization where SqlMethods.Like(c.Hierarchy, "%/12/%") select *;