C # Write SQL-like statements in List (that is, writing them to beginners)

This article is written to C # For Beginners. The veteran will not read it. It is actually about LINQ. Thank you for reminding me on the first floor.

In many cases, it is easy to pick out a list of elements from a relational table and use SQL statements. In fact, similar methods can also be used in the C # list, although the select (), where () and other statements are integrated in the list, the following methods are also feasible if your judgment rules are complex or you want to make it clear:

Assume that you have a class

public class People{    public string Name { get; set; }    public int Age { get; set; }}

And there are some initialization statements

List<People> PeopleList = new List<People>();PeopleList.Add(new People() { Name = "Haocheng Wu", Age = 24 });PeopleList.Add(new People() { Name = "Haocheng Wu", Age = 25 });PeopleList.Add(new People() { Name = "James Wu", Age = 23 });

You can use the following SQL statement-like method for select

List<string> SubPeopleNameList1 = (from people in PeopleList                              where people.Name == "Haocheng Wu" && people.Age == 24                              select people.Name).ToList<string>();

Of course, you can also use a row instead. 

List<string> SubPeopleNameList2 = PeopleList.Where(people => people.Name == "Haocheng Wu" && people.Age == 24).Select(people => people.Name).ToList();

However, it is clear that the first method is more clear, especially when the judgment conditions are quite complex.