Join Olivia Chiu Stone for an in-depth discussion in this video Use OfType to convert to IEnumerable, part of LINQ with C# Essential Training.
- LINQ works mainly with collections…that have implemented IEnumerable.…However, you may want to perform a query…on a collection that does not have…IEnumerable implemented.…An example of this is an ArrayList.…This program is linked to the same…SQL database I've been using.…If I try to run the query to order the strings,…I get an error.…To make this a valid data source for a LINQ query,…I'll use OfType to convert the ArrayList…to an IEnumerable before doing the OrderBy query.…
Now when I run the program,…I successfully have my ordered list of products.…If I have an element in the ArrayList…that is incompatible, OfType will ignore it.…So if I add another element to the ArrayList…that is a numeric,…and run the code,…the program ignored the added element…and omitted it from the sequence.…I can make the program throw an exception…when this happens by replacing…the OfType method with the Cast method.…
When working with SQL databases,…the sequences are of type IQueryable.…Unfortunately, not all LINQ queries…can interface with IQueryable such as SkipWhile.…
AuthorOlivia Chiu Stone
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
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