仅检索MongoDB集合中对象数组中查询到的匹配元素

Question

我的MongoDB结构是

{
    "_id": "QR00000017",
    "packagingTypeID": "PTI00010",
    "packages": [{
        "packageQRCode": "QR00000017_HR00000137_PTI00010_9",
        "packageID": "QR00000017_9"
    }, {
        "packageQRCode": "QR00000017_HR00000137_PTI00010_10",
        "packageID": "QR00000017_10"
    }, {
        "packageQRCode": "QR00000017_HR00000137_PTI00010_11",
        "packageID": "QR00000017_11"
    }, {
        "packageQRCode": "QR00000017_HR00000137_PTI00010_12",
        "packageID": "QR00000017_12"
    }, {
        "packageQRCode": "QR00000017_HR00000137_PTI00010_13",
        "packageID": "QR00000017_13"
    }, {
        "packageQRCode": "QR00000017_HR00000137_PTI00010_14",
        "packageID": "QR00000017_14"
    }, {
        "packageQRCode": "QR00000017_HR00000137_PTI00010_15",
        "packageID": "QR00000017_15"
    }]
  
}

现在，我在数组中输入了多个包in作为输入，希望只检索与mongodb示例"QR00000017_13“、"QR00000017_14”匹配的包in，如下面的输出所示

{
        "_id": "QR00000017",
        "packagingTypeID": "PTI00010",
        "packages": [{
            "packageQRCode": "QR00000017_HR00000137_PTI00010_13",
            "packageID": "QR00000017_13"
        }, {
            "packageQRCode": "QR00000017_HR00000137_PTI00010_14",
            "packageID": "QR00000017_14"
        }]
      
    }

我的代码是

packages_in_str=["QR00000017_13","QR00000017_14"];
Criteria usernameCriteria = Criteria.where("packages.packageID").in(packages_in_str); query.fields().include("packages.$");

我得到的输出是

{
"_id": "QR00000017",
    "packagingTypeID": "PTI00010",
    "packages": [{
        "packageQRCode": "QR00000017_HR00000137_PTI00010_13",
        "packageID": "QR00000017_13"
    }]
}

Answer 1

从docs

位置$运算符将an的内容限制为返回与数组上的查询条件匹配的第一个元素

如果要返回所有匹配项，则需要对$filter使用聚合