查询仅基于月份或年份选择文档

Question

在 MongoDB 中是否存在仅基于月份或年份选择文档的查询，类似于 mysql 中以下代码的等效项；

$q="SELECT * FROM projects WHERE YEAR(Date) = 2011 AND MONTH(Date) = 5";

我正在寻找 MongoDB 等价物，有人可以帮忙吗？

Answer 1

使用 aggregation framework 获取查询，特别是 Date Aggregation Operators $year 和 $month。为您提供上述查询的聚合管道如下所示：

var pipeline = [
    {
        "$project": {
            "year": { "$year": "$date" },
            "month": { "$month": "$date" },
            "other_fields": 1
         }
    },
    {
        "$match": {
            "year": 2011,
            "month": 5
        }
    }
]

db.project.aggregate(pipeline);

等效的 PHP 查询是：

$m = new MongoClient("localhost");
$c = $m->selectDB("examples")->selectCollection("project");

$pipeline = array(
    array(
        '$project' => array(
            "year" => array("$year" => '$date'),
            "month" => array("$month" => '$date'),
            "other_fields"   => 1,
        )
    ),    
    array(
        '$match' => array(
            "year" => 2011,
            "month" => 5,
        ),
    ),
);
$results = $c->aggregate($pipeline);
var_dump($results);