github地址：https://github.com/huyanping/Zebra-PHP-ArrayGroupBy
packagist地址：https://packagist.org/packages/jenner/array_group_by
为什么使用Zebra-PHP-ArrayGroupBy
在如下场景中，我们总是希望能够在php中使用类似mysql的groupby操作：
- SQL过于复杂，造成数据库运算效率低下
- 从数据库中读取出原始数据，在php中进行运算，增强代码重用率
- 其他非数据库场景的数组归并场景
Zebar-PHP-ArrayGroupBy能够做什么
- 对二维数组进行归并
- 归并的同时，支持对字段进行自定义处理
- 比SQL更灵活的自定义函数，你可以随意编写归并和字段合并函数
示例：
$records = [
[‘order_date‘ => ‘2014-01-01‘, ‘price‘ => 5],
[‘order_date‘ => ‘2014-01-02‘, ‘price‘ => 10],
[‘order_date‘ => ‘2014-01-03‘, ‘price‘ => 20],
[‘order_date‘ => ‘2015-01-04‘, ‘price‘ => 25],
];
$group_by_fields = [
‘order_date‘ => function($value){
return date(‘Y‘, strtotime($value));
}
];
$group_by_value = [
‘order_date‘ => [
‘callback‘ => function($value_array){
return substr($value_array[0], 0, 4);
},
‘as‘ => ‘year‘
],
‘price‘ => function($value_array){
return array_sum($value_array);
},
];
$grouped = \Jenner\Zebra\ArrayGroupBy::groupBy($records, $group_by_fields, $group_by_value);
print_r($grouped);
结果：
Array
(
[0] => Array
(
[year] => 2014
[price] => 35
)
[1] => Array
(
[year] => 2015
[price] => 25
)
)
你也可以使用链式方法调用，对数据进行多次汇总，更加灵活：
$records = [
[‘bill_time‘=>‘2014-01-01 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-01 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-01 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-01 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-01 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-01 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-02 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-02 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-02 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-02 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-02 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-03 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-03 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-03 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-03 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-03 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-04 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
[‘bill_time‘=>‘2014-01-04 00:00:00‘, ‘price‘=>1, ‘cnt‘=>3,],
];
$group_by_fields = [
‘bill_time‘ => function($field){
return substr($field, 0, 10);
}
];
$group_by_values = [
‘bill_time‘ => function($field_values){
return substr($field_values[0], 0, 10);
},
‘price‘ => function($field_values){
return array_sum($field_values);
},
‘cnt‘ => function($field_values){
return array_sum($field_values);
}
];
$week_fields = [
‘bill_time‘ => function($field){
return date(‘w‘, strtotime($field));
}
];
$week_values = [
‘bill_time‘ => function($field_values){
return date(‘w‘, strtotime($field_values[0]));
},
‘price‘ => function($field_values){
return array_sum($field_values);
},
‘cnt‘ => function($field_values){
return array_sum($field_values);
}
];
$grouped = (new \Jenner\Zebra\ArrayGroupBy($records))->groupByField($group_by_fields)->groupByValue($group_by_values)->groupByField($week_fields)->groupByValue($week_values)->get();
print_r($grouped);
举例
- 归并过程中，实现对结果的中值计算
- 归并过程中，对时间字段进行自定义处理，例如归并每5分钟的数据
- 等等
原创文章，转载请注明： 转载自始终不够
本文链接地址: PHP模拟SQL的GROUP BY算法
