PHPLinq ：用SQL语法操作PHP数组。

官网：http://phplinq.codeplex.com/

Examples

Examples can be found in the test package in the latest release.

A basic example

Let's say we have an array of strings and want to select only the strings whose length is < 5. The PHPLinq way of achieving
this would be the following:

// Create data source
$names = array("John", "Peter", "Joe", "Patrick", "Donald", "Eric");

$result = from('$name')->in($names)
->where('$name => strlen($name) < 5')
->select('$name');

Feels familiar to SQL? Yes indeed! No more writing a loop over this array, checking the string's length, and adding it to a
temporary variable.

You may have noticed something strange... What's that $name => strlen($name) < 5 doing? This piece of code is compiled to an
anonymous function or Lambda expression under the covers. This function accepts a parameter $name, and returns a boolean value based on the expression strlen($name) < 5.

An advanced example

There are lots of other examples available in the PHPLinq download, but here's an advanced one... Let's say we have an array
of Employee objects. This array should be sorted by Employee name, then Employee age. We want only Employees whose name has a length of 4 characters. Next thing: we do not want an Employee instance in our result. Instead, the returning array should contain
objects containing an e-mail address and a domain name.

First of all, let's define our data source:

class Employee {
public $Name;
public $Email;
public $Age;

public function __construct($name, $email, $age) {
$this->Name     = $name;
$this->Email     = $email;
$this->Age        = $age;
}
}

$employees = array(
new Employee('Maarten', 'maarten@example.com', 24),
new Employee('Paul', 'paul@example.com', 30),
new Employee('Bill', 'bill.a@example.com', 29),
new Employee('Bill', 'bill.g@example.com', 28),
new Employee('Xavier', 'xavier@example.com', 40)
);

Now for the PHPLinq query:

$result = from('$employee')->in($employees)
->where('$employee => strlen($employee->Name) == 4')
->orderBy('$employee => $employee->Name')
->thenByDescending('$employee => $employee->Age')
->select('new {
"EmailAddress" => $employee->Email,
"Domain" => substr($employee->Email, strpos($employee->Email, "@") + 1)
}');

Again, you may have noticed something strange... What's this new { } thing doing? Actually, this is converted to an anonymous
type under the covers. new { "name" => "test" } is evaluated to an object containing the property "name" with a value of "test".