---
title: "What is the purpose of the \"AsEnumerable\" and \"AsQueryable\" methods in LINQ?"  
description: "What is the purpose of the \"AsEnumerable\" and \"AsQueryable\" methods in LINQ?"  
author: "Sandra Emily"  
published: 2023-09-12  
updated: 2023-09-25  
canonical: https://www.mindstick.com/forum/159875/what-is-the-purpose-of-the-asenumerable-and-asqueryable-methods-in-linq  
category: "c#"  
tags: ["c#", "linq", "linq to sql"]  
reading_time: 3 minutes  

---

# What is the purpose of the "AsEnumerable" and "AsQueryable" methods in LINQ?

What is the [purpose](https://yourviews.mindstick.com/view/247/no-fail-policy-failing-its-purpose) of the 'AsEnumerable' and 'AsQueryable' [methods](https://www.mindstick.com/articles/13060/runny-nose-remedy-methods-that-work-best) in [LINQ](https://www.mindstick.com/articles/12007/language-integrated-query-linq-queries)?

## Replies

### Reply by Aryan Kumar

In LINQ (Language Integrated Query), the **AsEnumerable()** and **AsQueryable()** methods are used to change the data source type temporarily during a query. They are typically used to cast or adapt an existing collection or data source to a different interface type, depending on the requirements of the query and the underlying data source.

Here's a brief explanation of the purpose and use cases for both methods:

**AsEnumerable()**:

- **Purpose**: The **AsEnumerable()** method is primarily used to convert a data source or collection into an **IEnumerable<T>**. This is often done to shift the query processing from being database-specific (if you're using LINQ to Entities or LINQ to SQL) to in-memory processing using LINQ to Objects.
- **Use Cases**:

   - When you want to perform further LINQ operations on the data in memory after retrieving it from a database. This can be useful when you want to use LINQ to Objects methods that are not supported in LINQ to Entities or LINQ to SQL.
   - To transition from a database query to an in-memory query while maintaining deferred execution (i.e., postponing the execution of the query until it's actually needed).

```plaintext
var query = dbContext.Orders
                  .Where(order => order.CustomerId == customerId)
                  .AsEnumerable()
                  .Where(order => order.OrderDate.Year == 2023)
                  .ToList();
```

**AsQueryable()**:

- **Purpose**: The **AsQueryable()** method is used to convert an **IEnumerable<T>** or any other collection type into an **IQueryable<T>**. This is often done to enable query composition and deferred execution when working with in-memory collections or other non-queryable data sources.
- **Use Cases**:

   - When you want to apply additional query operations (such as filtering, sorting, or projecting) on an in-memory collection and want to leverage deferred execution, which allows you to compose complex queries efficiently.
   - To bridge the gap between LINQ to Objects and LINQ to Entities, making it possible to use common query operators on both types of data sources.

Example:

```plaintext
var queryableData = inMemoryCollection.AsQueryable();
var result = queryableData.Where(item => item.SomeProperty == someValue).OrderBy(item => item.OtherProperty);
```

In summary, **AsEnumerable()** is used to switch from a queryable data source (e.g., database) to an in-memory collection for further processing, while **AsQueryable()** is used to introduce queryability to an in-memory collection, allowing you to apply LINQ operations with deferred execution. The choice between these methods depends on whether you want to transition from queryable to in-memory or vice versa and whether you need deferred execution or not.


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Original Source: https://www.mindstick.com/forum/159875/what-is-the-purpose-of-the-asenumerable-and-asqueryable-methods-in-linq

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