Csharp/CSharp Tutorial/LINQ/OrderBy — различия между версиями
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Версия 18:31, 26 мая 2010
Содержание
- 1 An array of string values sorted first by length, then sorted alphabetically, using a case-insentive comparison.
- 2 First OrderBy Prototype
- 3 Icecreams with Least Price
- 4 Multi Level Ordering
- 5 Not in Top Five Customers by Sales
- 6 Order by descending
- 7 OrderBy: prints an alphabetically sorted version of a string array
- 8 OrderBy with customized Comparer
- 9 OrderBy with passing a lambda function
- 10 Ordered by PetName
- 11 Order Method Syntax
- 12 Order Query Results
- 13 products sorted alphabetically by the product name
- 14 products sorted by the number of units of each product that are in stock
- 15 sorted alphabetically in descending order, using a case insensitive comparision.
- 16 Sorted join query
- 17 Sorting strings in a file
- 18 Sort object by its property
- 19 string array sorted by the length each element
- 20 Top Five Customers by Sales
- 21 Using a compound orderby to sort a list of digits first by length of their name, and then alphabetically.
- 22 Using a compound orderby to sort a list of products, first by category, and then by unit price, from highest to lowest.
- 23 Using orderby clause to order result
- 24 Where with OrderBy
An array of string values sorted first by length, then sorted alphabetically, using a case-insentive comparison.
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class CaseInsensitiveComparer : IComparer<string> {
public int Compare(string x, string y) { return string.rupare(x, y, true); }
} public class MainClass {
public static void Main() { string[] words = { "a", "A", "b", "B", "C", "c" }; var sortedWords = words.OrderBy(a => a.Length) .ThenBy(a => a, new CaseInsensitiveComparer()); Console.Write(sortedWords); }
}</source>
First OrderBy Prototype
<source lang="csharp">using System; using System.Linq; using System.Collections; using System.Collections.Generic; public class MainClass {
public static void Main() { string[] presidents = {"ant", "arding", "arrison", "eyes", "over", "ackson"}; IEnumerable<string> items = presidents.OrderBy(s => s.Length); foreach (string item in items) Console.WriteLine(item); }
}</source>
Icecreams with Least Price
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Linq.Expressions; using System.Xml.Linq;
class Program { static void Main(string[] args) { List<Icecream> icecreamsList3 = new List<Icecream>{ new Icecream("A", 10.5), new Icecream("B", 9.80 ), new Icecream("C", 7.5) }; var icecreamswithLeastPrice =from Ice in icecreamsList3 where Ice.price <= 10 select new { Ice.name, Ice.price }; foreach (var ice in icecreamswithLeastPrice) { Console.WriteLine(ice.name + " " + ice.price); } var count = icecreamsList3.Count<Icecream>(Ice => Ice.price <= 10); Console.WriteLine(count); } }
public class Icecream { public string name; public double price; public Icecream(string name, double price) { this.name = name; this.price = price; } }</source>
Multi Level Ordering
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;
class Customer { public string ID { get; set; } public string City { get; set; } public string Country { get; set; } public string Region { get; set; } public decimal Sales { get; set; } } class Program { static void Main(string[] args) { List<Customer> customers = new List<Customer> { new Customer { ID="Q", City="London", Country="UK", Region="Europe", Sales=8000 }, new Customer { ID="R", City="Beijing", Country="China", Region="Asia", Sales=9000 }, new Customer { ID="T", City="Lima", Country="Peru", Region="South America", Sales=2002 } }; var queryResults = from c in customers orderby c.Region, c.Country descending, c.City select new { c.ID, c.Region, c.Country, c.City } ; foreach (var item in queryResults) { Console.WriteLine(item); } } }</source>
Not in Top Five Customers by Sales
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;
class Customer { public string ID { get; set; } public string City { get; set; } public string Country { get; set; } public string Region { get; set; } public decimal Sales { get; set; } } class Program { static void Main(string[] args) { List<Customer> customers = new List<Customer> { new Customer { ID="N", City="Los Angeles", Country="USA", Region="North America", Sales=5000 }, new Customer { ID="O", City="Cairo", Country="Egypt", Region="Africa", Sales=6000 }, new Customer { ID="R", City="Beijing", Country="China", Region="Asia", Sales=9000 }, new Customer { ID="T", City="Lima", Country="Peru", Region="South America", Sales=2002 } }; var queryResults = from c in customers orderby c.Sales descending select new { c.ID, c.City, c.Country, c.Sales } ; Console.WriteLine("Customers Not In Top Five"); foreach (var item in queryResults.Skip(5)) { Console.WriteLine(item); }
} }</source>
Order by descending
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;
class Employee { public string Name { get; set; } public decimal Salary { get; set; } } class Department { public string Name { get; set; } List<Employee> employees = new List<Employee>(); public IList<Employee> Employees { get { return employees; } } } class Company { public string Name { get; set; } List<Department> departments = new List<Department>(); public IList<Department> Departments { get { return departments; } } } class SalaryReport { static void Main() { var company = new Company { Name = "A", Departments = { new Department { Name = "Development", Employees = { new Employee { Name = "T", Salary = 75000m }, new Employee { Name = "D", Salary = 45000m }, new Employee { Name = "M", Salary = 150000m } } }, new Department { Name = "Marketing", Employees = { new Employee { Name = "Z", Salary = 200000m }, new Employee { Name = "X", Salary = 120000m } } } } }; var query = company.Departments .Select(dept => new { dept.Name, Cost = dept.Employees.Sum(person => person.Salary) }) .OrderByDescending(deptWithCost => deptWithCost.Cost); foreach (var item in query) { Console.WriteLine(item); } } }</source>
OrderBy: prints an alphabetically sorted version of a string array
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class MainClass {
public static void Main() { string[] words = { "C", "a", "b" }; var sortedWords = from w in words orderby w select w; Console.WriteLine("The sorted list of words:"); foreach (var w in sortedWords) { Console.WriteLine(w); } }
}</source>
OrderBy with customized Comparer
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class CaseInsensitiveComparer : IComparer<string> {
public int Compare(string x, string y) { return string.rupare(x, y, true); }
} public class MainClass {
public static void Main() { string[] words = { "a", "A", "b", "B", "C", "c" }; var sortedWords = words.OrderBy(a => a, new CaseInsensitiveComparer());
}
}</source>
OrderBy with passing a lambda function
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class CaseInsensitiveComparer : IComparer<string> {
public int Compare(string x, string y) { return string.rupare(x, y, true); }
} public class MainClass {
public static void Main() { string[] words = { "a", "A", "b", "B", "C", "c" }; var sortedWords = words.OrderBy(a => a, new CaseInsensitiveComparer());
}
}</source>
Ordered by PetName
<source lang="csharp">using System; using System.Collections.Generic; using System.Text; using System.Xml.Linq; using System.Linq;
class Car { public string PetName; public string Color; public int Speed; public string Make; public override string ToString() { return string.Format("Make={0}, Color={1}, Speed={2}, PetName={3}",Make, Color, Speed, PetName); } } class Program { static void Main(string[] args) { Car[] myCars = new []{ new Car{ PetName = "A", Color = "Silver", Speed = 100, Make = "BMW"}, new Car{ PetName = "B", Color = "Black", Speed = 55, Make = "VW"}, new Car{ PetName = "C", Color = "White", Speed = 43, Make = "Ford"} }; var subset = from c in myCars orderby c.PetName select c; foreach (Car c in subset) { Console.WriteLine(c.ToString()); } } }</source>
Order Method Syntax
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;
class Program { static void Main(string[] args) { string[] names = {"Zheng", "Smith" }; var queryResults = names.OrderBy(n => n).Where(n => n.StartsWith("S")); foreach (var item in queryResults) { Console.WriteLine(item); } } }</source>
Order Query Results
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;
class Program { static void Main(string[] args) { string[] names = { "Zheng", "Smith", "Small" }; var queryResults = from n in names where n.StartsWith("S") orderby n select n; foreach (var item in queryResults) { Console.WriteLine(item); } } }</source>
products sorted alphabetically by the product name
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class MainClass {
public static void Main() { List<Product> products = GetProductList(); var sortedProducts = from p in products orderby p.ProductName select p; Console.WriteLine(sortedProducts); } static List<Product> GetProductList() { List<Product> empTree = new List<Product>(); empTree.Add(new Product { ProductName = "A", Category = "O", UnitPrice = 12, UnitsInStock = 5, Total = 36, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "B", Category = "O", UnitPrice = 2, UnitsInStock = 4, Total = 35, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "C", Category = "O", UnitPrice = 112, UnitsInStock = 3, Total = 34, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "D", Category = "O", UnitPrice = 112, UnitsInStock = 0, Total = 33, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "E", Category = "O", UnitPrice = 1112, UnitsInStock = 2, Total = 32, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "F", Category = "O", UnitPrice = 11112, UnitsInStock = 0, Total = 31, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); return empTree; }
} class Product : IComparable<Product> {
public string ProductName { get; set; } public string Category { get; set; } public int UnitPrice { get; set; } public int UnitsInStock { get; set; } public int Total { get; set; } public DateTime OrderDate { get; set; } public int Id { get; set; } public override string ToString() { return String.Format("Id: {0}, Name: {1} , Category: {3}", this.Id, this.ProductName, this.Category); } int IComparable<Product>.rupareTo(Product other) { if (other == null) return 1; if (this.Id > other.Id) return 1; if (this.Id < other.Id) return -1; return 0; }
}</source>
products sorted by the number of units of each product that are in stock
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class MainClass {
public static void Main() { List<Product> products = GetProductList(); var sortedProducts = from p in products orderby p.UnitsInStock descending select p; Console.Write(sortedProducts); } static List<Product> GetProductList() { List<Product> empTree = new List<Product>(); empTree.Add(new Product { ProductName = "A", Category = "O", UnitPrice = 12, UnitsInStock = 5, Total = 36, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "B", Category = "O", UnitPrice = 2, UnitsInStock = 4, Total = 35, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "C", Category = "O", UnitPrice = 112, UnitsInStock = 3, Total = 34, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "D", Category = "O", UnitPrice = 112, UnitsInStock = 0, Total = 33, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "E", Category = "O", UnitPrice = 1112, UnitsInStock = 2, Total = 32, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "F", Category = "O", UnitPrice = 11112, UnitsInStock = 0, Total = 31, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); return empTree; }
} class Product : IComparable<Product> {
public string ProductName { get; set; } public string Category { get; set; } public int UnitPrice { get; set; } public int UnitsInStock { get; set; } public int Total { get; set; } public DateTime OrderDate { get; set; } public int Id { get; set; } public override string ToString() { return String.Format("Id: {0}, Name: {1} , Category: {3}", this.Id, this.ProductName, this.Category); } int IComparable<Product>.rupareTo(Product other) { if (other == null) return 1; if (this.Id > other.Id) return 1; if (this.Id < other.Id) return -1; return 0; }
}</source>
sorted alphabetically in descending order, using a case insensitive comparision.
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class CaseInsensitiveComparer : IComparer<string> {
public int Compare(string x, string y) { return string.rupare(x, y, true); }
} public class MainClass {
public static void Main() { string[] words = { "a", "A", "b", "B", "C", "c" }; var sortedWords = words.OrderByDescending(a => a, new CaseInsensitiveComparer()); }
}</source>
Sorted join query
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;
public class Customer { public string FirstName { get; set; } public string LastName { get; set; } public string EmailAddress { get; set; } public override string ToString(){ return string.Format("{0} {1}\nEmail: {2}",FirstName, LastName, EmailAddress); } } public class Address { public string Name { get; set; } public string Street { get; set; } public string City { get; set; } public override string ToString() { return string.Format("{0}, {1}", Street, City); } } public class CustomerAddress { public Customer Customer { get; set; } public Address Address { get; set; } } public class Tester { static void Main() { List<Customer> customers = new List<Customer> { new Customer { FirstName = "A", LastName = "B", EmailAddress = "o@a.ru"}, new Customer { FirstName = "B", LastName = "C", EmailAddress = "k@a.ru" }, new Customer { FirstName = "D", LastName = "C", EmailAddress = "d@a.ru" }, new Customer { FirstName = "F", LastName = "G", EmailAddress = "j@a.ru" }, new Customer { FirstName = "L", LastName = "H", EmailAddress = "l@a.ru" } }; List<Address> addresses = new List<Address> { new Address { Name = "J", Street = "165 Main", City = "City 1" }, new Address { Name = "K H", Street = "3207 Way", City = "Cith 2" }, new Address { Name = "J G", Street = "800 Blvd.", City = "City 3" }, new Address { Name = "Mary", Street = "7 Ave", City = "City 4" }, new Address { Name = "Kate", Street = "2251 Avenue", City = "City 5" } }; var result = from customer in customers join address in addresses on string.Format("{0} {1}", customer.FirstName, customer.LastName) equals address.Name orderby customer.LastName, address.Street descending select new { Customer = customer, Address = address }; foreach (var ca in result) { Console.WriteLine(string.Format("{0}\nAddress: {1}", ca.Customer, ca.Address)); } } }</source>
Sorting strings in a file
<source lang="csharp">using System; using System.IO; using System.Collections.Generic; using System.Linq; using System.Text; using System.Linq.Expressions; using System.Xml.Linq;
class Program { static void Main(string[] args) { List<string> strs = new List<string>(); using( StreamReader sReader = new StreamReader("data.txt")) { string str; str = sReader.ReadLine(); while (str != null) { strs.Add(str); } } IEnumerable<string> i = from name in strs orderby name descending select name; foreach (string nam in i) { Console.WriteLine(nam); } } }</source>
Sort object by its property
<source lang="csharp">using System; using System.Collections.Generic; using System.ruponentModel;
class Film { public string Name { get; set; } public int Year { get; set; } public override string ToString() { return string.Format("Name={0}, Year={1}", Name, Year); } } class MainClass { static void Main() { var films = new List<Film> { new Film {Name="J", Year=1975}, new Film {Name="H", Year=2000}, new Film {Name="T", Year=1995} }; Action<Film> print = film => Console.WriteLine(film); Console.WriteLine("All films"); films.ForEach(print); Console.WriteLine(); Console.WriteLine("Oldies"); films.FindAll(film => film.Year < 1980).ForEach(print); Console.WriteLine(); Console.WriteLine("Sorted"); films.Sort((f1, f2) => f1.Name.rupareTo(f2.Name)); films.ForEach(print); } }</source>
string array sorted by the length each element
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class MainClass {
public static void Main() { string[] words = { "abc", "bcd", "def" }; var sortedWords = from w in words orderby w.Length select w; Console.WriteLine("The sorted list of words (by length):"); foreach (var w in sortedWords) { Console.WriteLine(w); } }
}</source>
Top Five Customers by Sales
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;
class Customer { public string ID { get; set; } public string City { get; set; } public string Country { get; set; } public string Region { get; set; } public decimal Sales { get; set; } } class Program { static void Main(string[] args) { List<Customer> customers = new List<Customer> { new Customer { ID="N", City="Los Angeles", Country="USA", Region="North America", Sales=5000 }, new Customer { ID="O", City="Cairo", Country="Egypt", Region="Africa", Sales=6000 }, new Customer { ID="R", City="Beijing", Country="China", Region="Asia", Sales=9000 }, new Customer { ID="T", City="Lima", Country="Peru", Region="South America", Sales=2002 } }; var queryResults = from c in customers orderby c.Sales descending select new { c.ID, c.City, c.Country, c.Sales } ; Console.WriteLine("Top Five Customers by Sales"); foreach (var item in queryResults.Take(5)) { Console.WriteLine(item); }
} }</source>
Using a compound orderby to sort a list of digits first by length of their name, and then alphabetically.
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class MainClass {
public static void Main() { string[] digits = { "zero", "one", "two", "three"}; var sortedDigits = from d in digits orderby d.Length, d select d; Console.WriteLine("Sorted digits:"); foreach (var d in sortedDigits) { Console.WriteLine(d); } }
}</source>
Using a compound orderby to sort a list of products, first by category, and then by unit price, from highest to lowest.
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text; public class MainClass {
public static void Main() { List<Product> products = GetProductList(); var sortedProducts = from p in products orderby p.Category, p.UnitPrice descending select p; foreach (var s in sortedProducts) { Console.Write(s); } } static List<Product> GetProductList() { List<Product> empTree = new List<Product>(); empTree.Add(new Product { ProductName = "A", Category = "O", UnitPrice = 12, UnitsInStock = 5, Total = 36, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "B", Category = "O", UnitPrice = 2, UnitsInStock = 4, Total = 35, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "C", Category = "O", UnitPrice = 112, UnitsInStock = 3, Total = 34, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "D", Category = "O", UnitPrice = 112, UnitsInStock = 0, Total = 33, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "E", Category = "O", UnitPrice = 1112, UnitsInStock = 2, Total = 32, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); empTree.Add(new Product { ProductName = "F", Category = "O", UnitPrice = 11112, UnitsInStock = 0, Total = 31, OrderDate = new DateTime(2005, 1, 1), Id = 1 }); return empTree; }
} class Product : IComparable<Product> {
public string ProductName { get; set; } public string Category { get; set; } public int UnitPrice { get; set; } public int UnitsInStock { get; set; } public int Total { get; set; } public DateTime OrderDate { get; set; } public int Id { get; set; } public override string ToString() { return String.Format("Id: {0}, Name: {1} , Category: {3}", this.Id, this.ProductName, this.Category); } int IComparable<Product>.rupareTo(Product other) { if (other == null) return 1; if (this.Id > other.Id) return 1; if (this.Id < other.Id) return -1; return 0; }
}</source>
Using orderby clause to order result
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; using System.Text;
class Program { static void Main(string[] args) { string[] names = { "Zheng", "Smith", "Small" }; var queryResults = from n in names where n.StartsWith("S") orderby n select n; foreach (var item in queryResults) { Console.WriteLine(item); } } }</source>
Where with OrderBy
<source lang="csharp">using System; using System.Collections.Generic; using System.Linq; public class MainClass {
public static void Main() { string[] names = { "J", "P", "G", "Pa" }; IEnumerable<string> query = names.Where(n => n.Contains("a")) .OrderBy(n => n.Length) .Select(n => n.ToUpper()); }
}</source>