AspNetCore.Docs/aspnetcore/includes/mvc-intro/search1.md

# Add search to an ASP.NET Core MVC app

By [Rick Anderson](https://twitter.com/RickAndMSFT)

In this section you add search capability to the `Index` action method that lets you search movies by *genre* or *name*.

Update the `Index` method with the following code:
<!--
[!code-html[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie/Views/Shared/_Layout.cshtml?highlight=7,31)]
-->

[!code-csharp[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie/Controllers/MoviesController.cs?name=snippet_1stSearch)]

The first line of the `Index` action method creates a [LINQ](/dotnet/standard/using-linq) query to select the movies:

```csharp
var movies = from m in _context.Movie
             select m;
```

The query is *only* defined at this point, it has **not** been run against the database.

If the `searchString` parameter contains a string, the movies query is modified to filter on the value of the search string:

[!code-csharp[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie/Controllers/MoviesController.cs?name=snippet_SearchNull2)]

The `s => s.Title.Contains()` code above is a [Lambda Expression](/dotnet/csharp/programming-guide/statements-expressions-operators/lambda-expressions). Lambdas are used in method-based [LINQ](/dotnet/standard/using-linq) queries as arguments to standard query operator methods such as the [Where](/dotnet/api/system.linq.enumerable.where) method or `Contains` (used in the code above). LINQ queries are not executed when they're defined or when they're modified by calling a method such as `Where`, `Contains`  or `OrderBy`. Rather, query execution is deferred.  That means that the evaluation of an expression is delayed until its realized value is actually iterated over or the `ToListAsync` method is called. For more information about deferred query execution, see [Query Execution](/dotnet/framework/data/adonet/ef/language-reference/query-execution).

Note: The [Contains](/dotnet/api/system.data.objects.dataclasses.entitycollection-1.contains) method is run on the database, not in the c# code shown above. The case sensitivity on the query depends on the database and the collation. On SQL Server, [Contains](/dotnet/api/system.data.objects.dataclasses.entitycollection-1.contains) maps to [SQL LIKE](/sql/t-sql/language-elements/like-transact-sql), which is case insensitive. In SQLite, with the default collation, it's case sensitive.

Navigate to `/Movies/Index`. Append a query string such as `?searchString=Ghost` to the URL. The filtered movies are displayed.

![Index view](~/tutorials/first-mvc-app/search/_static/ghost.png)

If you change the signature of the `Index` method to have a parameter named `id`, the `id` parameter will match the optional `{id}` placeholder for the default routes set in *Startup.cs*.

[!code-csharp[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie/Startup.cs?highlight=5&name=snippet_1)]