What is query splitting in Entity Framework and why would you use it?

Experience Level: Senior
Tags: Entity Framework

Answer

Query splitting is a feature in Entity Framework that allows you to split a query into multiple smaller queries. This can help improve performance by reducing the amount of data that needs to be loaded into memory.

By default, Entity Framework loads all related data for an entity when you use the Include method. This can lead to performance issues when you have large amounts of data or complex relationships between entities.

Query splitting allows you to load only the data you need by splitting the query into smaller queries. You can use the AsSplitQuery method to split the query into multiple smaller queries.

Here’s an example of how to use AsSplitQuery method:

var orders = context.Orders
    .Include(o => o.Customer)
        .ThenInclude(c => c.Address)
    .AsSplitQuery()
    .ToList();

This code retrieves all orders, their associated customers, and the addresses of those customers in multiple queries.
Entity Framework Core
Entity Framework Core

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