What is queryable?

Queryable is an interface in the .NET framework that provides a standard query infrastructure that allows developers to express their queries using a language syntax similar to SQL. The IQueryable interface extends IEnumerable, which means it is capable of iterating through a collection of objects but also provides additional querying capabilities.

By leveraging the IQueryable interface, developers can write queries against different types of data sources, including databases, XML documents, and object collections. When a query is executed against a data source, the IQueryable interface generates the appropriate SQL or other query syntax, which is sent to the data source for execution.

The benefit of using IQueryable is that it allows developers to create more flexible and efficient queries that are capable of being optimized for the specific data source being queried. Additionally, the use of IQueryable helps to reduce the amount of code that developers need to write to interact with databases or other data sources, as the interface provides a standard way to interact with all data sources that support it.