Скачать или смотреть How to Efficiently Translate Linq/SQL to Lambda in C#

Learn how to swiftly translate Linq/SQL queries into Lambda expressions in C-. This guide offers a clear breakdown for C- developers.
---
This video is based on the question https://stackoverflow.com/q/73614787/ asked by the user 'Anarch' ( https://stackoverflow.com/u/9490226/ ) and on the answer https://stackoverflow.com/a/73614882/ provided by the user 'Cetin Basoz' ( https://stackoverflow.com/u/894977/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to translate Linq/SQL to Lambda in c-

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Efficiently Translate Linq/SQL to Lambda in C-

In the world of C- programming, particularly when utilizing Entity Framework Core, developers frequently encounter scenarios where they need to convert LINQ (Language Integrated Query) expressions to Lambda syntax. This transition can be vital for optimizing queries or simply for preference. In this guide, we'll explore how to translate a specific LINQ query into its Lambda equivalent, providing step-by-step insights along the way.

The Problem: Translating LINQ to Lambda

Consider the following LINQ query that retrieves information about hospitals and their associated sick rooms:

[[See Video to Reveal this Text or Code Snippet]]

Both newcomers and seasoned developers often find it challenging to make such translations. Let's dissect how to change this LINQ query into a Lambda expression.

The Solution: Using Lambda Expressions

The Equivalent Lambda Expression

To translate the provided LINQ query into a Lambda expression, here’s how you can do it:

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of the Code

Context: _ctx.Hospital is the context that represents the hospitals in our database.

Select: The Select method is used to project each hospital into a new anonymous type containing:

HospitalId

City

HospitalImage

NumberOfFloors, which is calculated using Max on h.SickRooms to find the maximum FloorId.

NumberOfApartments, which counts the number of sick rooms associated with the hospital using Count.

Key Takeaways

Model Relationships: It’s essential to have the correct model relationships in your Entity Framework setup. The translation assumes there is a navigation property from Hospital to SickRooms (h.SickRooms).

Syntax Variation: While LINQ query syntax and Lambda syntax may seem different, both ultimately perform similar operations. Understanding both formats enhances your flexibility as a developer.

Performance Consideration: Lambda expressions can sometimes lead to more performant queries given their concise nature, especially in scenarios with complex filters or manipulations.

Conclusion

Translating LINQ to Lambda expressions is straightforward once you grasp the basics of the syntax and relationship between entities in your database. With this knowledge, you can enhance your C- programming skills and streamline your data manipulation processes. Embrace both LINQ and Lambda to become a more versatile programmer in the .NET landscape!

Feel free to reference this guide whenever you encounter similar translation tasks, and happy coding!