If you've ever used Language Integrated Query (LINQ) before, you'll feel right at home with EF Core. The DbSet collection, which we've used to manipulate objects' states, implements the IQueryable interface that defines many querying operators that are later transformed into SQL statements by the database provider you've used. 

For example, the GiveNTake application allows the user to search for products that were published on a specific date. Here is a shortened version of how it is done:

[HttpGet("search/{date:datetime}/{keyword}/")]
public async Task<IActionResult> Search(DateTime date, string keyword)
{
    var products = await _context.Products      
        .Where(p => p.Title.Contains(keyword))
        .Where(p => p.PublishDate.Date == date.Date)
        .ToListAsync();

    // returning a response with the found products
}

The Where operator creates a filter on the IQueryable<Product> that the Products DbSet collection implements. LINQ has a composable and deferred execution model, where each operator adds another layer on the result returned from the previous operator, but the query itself won't be queried unless explicitly told so. Whenever an iteration is made on the result of the query, or when any completion operator is used, the query is executed and the results are returned to the applications. This includes running a foreach statement, using a conversion operator, such as ToListAsync(), or an operator such Count(), which returns the amount of results.

There are many LINQ operators you can use in your queries—more than this book can cover. However, I summarized some of what I believe are the most useful ones in this table: