Join Olivia Stone for an in-depth discussion in this video Create hierachy in a dataset, part of LINQ with C# Essential Training.
- View Offline
- Exercise Files
- The structure of an inner join is lackluster.…In my example some customers have multiple…distributors they can pick from…which adds a separate entry for each match.…It would be better to receive the results…in a hierarchical fashion,…where for each customer a list of distributors is returned.…To accomplish that I'll use a GroupJoin.…When executing a GroupJoin the elements…of the left sequence are associated…with one or more matching elements…in the right sequence.…This is also called an"Outer Join"…because the resulting sequence…will include the elements in the left sequence…that are outside of the overlapping areas.…
GroupJoin provides a similar functionality as Join,…but instead of returning a flat structure…it can return a structured result…grouped by each outer element in the resource sequence.…If no matches are found, it will produce…an empty array for that item…as seen here with customer Brock.…To accomplish a GroupJoin I'll add…an into expression to the join clause.…I'll cover the details about the into keyword…
In LINQ with C# Essential Training, engineer Olivia Chiu introduces techniques for querying, updating, and transforming data with LINQ. She covers standard queries—such as finding overlaps in two datasets and creating hierarchies—as well as complex chained queries. She also shows how to group and join LINQ queries with lambda expressions, and use LINQ to query SQL databases and XML documents. Last but not least, Olivia provides tips for optimizing the performance of your queries.
- Creating and executing a LINQ query
- Returning results
- Changing the data source type
- Performing standard queries
- Working with lambda expressions
- Chaining and complex queries
- Querying SQL and XML
- Performing tree queries
- Using sequences, elements, and scalars
- Allocating memory
Skill Level Intermediate
1. Introduction to LINQ
Common use cases1m 45s
2. Basic LINQ Queries
3. Data Transformation
Return results as a new type1m 39s
4. Type Relationships
5. Standard Queries
6. Lambda Expressions
7. Complex Queries
8. LINQ to SQL
9. LINQ to XML
10. Other Operators
- Mark as unwatched
- Mark all as unwatched
Are you sure you want to mark all the videos in this course as unwatched?
This will not affect your course history, your reports, or your certificates of completion for this course.Cancel
Take notes with your new membership!
Type in the entry box, then click Enter to save your note.
1:30Press on any video thumbnail to jump immediately to the timecode shown.
Notes are saved with you account but can also be exported as plain text, MS Word, PDF, Google Doc, or Evernote.