{"id":207680,"date":"2025-07-08T13:32:24","date_gmt":"2025-07-08T05:32:24","guid":{"rendered":"https:\/\/server.hk\/cnblog\/207680\/"},"modified":"2025-07-08T13:32:24","modified_gmt":"2025-07-08T05:32:24","slug":"%e5%a6%82%e4%bd%95%e5%a1%ab%e5%85%85%e5%a4%96%e9%83%a8%e5%ad%97%e6%ae%b5-id-%e7%9a%84-mongodb-%e6%95%b0%e7%bb%84%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/207680\/","title":{"rendered":"\u5982\u4f55\u586b\u5145\u5916\u90e8\u5b57\u6bb5 ID \u7684 MongoDB \u6570\u7ec4\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

\u5f53\u524d\u4f4d\u7f6e\uff1a ><\/span> ><\/span> ><\/span> ><\/span> \u5982\u4f55\u586b\u5145\u5916\u90e8\u5b57\u6bb5 ID \u7684 MongoDB \u6570\u7ec4\uff1f<\/span><\/p>\n

\u6765\u6e90\uff1astackoverflow<\/span>
\n2024-04-24 16:18:33<\/span>
\n<\/i>0\u6d4f\u89c8<\/span>
\n<\/i>\u6536\u85cf<\/span> <\/p>\n

\u5b66\u4e60\u77e5\u8bc6\u8981\u5584\u4e8e\u601d\u8003\uff0c\u601d\u8003\uff0c\u518d\u601d\u8003\uff01\u4eca\u5929\u5c0f\u7f16\u5c31\u7ed9\u5927\u5bb6\u5e26\u6765\u300a\u5982\u4f55\u586b\u5145\u5916\u90e8\u5b57\u6bb5 ID \u7684 MongoDB \u6570\u7ec4\uff1f\u300b<\/span>\uff0c\u4ee5\u4e0b\u5185\u5bb9\u4e3b\u8981\u5305\u542b<\/span>\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u4f60\u6b63\u5728\u5b66\u4e60\u6216\u51c6\u5907\u5b66\u4e60Golang<\/span>\uff0c\u5c31\u90fd\u4e0d\u8981\u9519\u8fc7\u672c\u6587\u5566~\u8ba9\u6211\u4eec\u4e00\u8d77\u6765\u770b\u770b\u5427\uff0c\u80fd\u5e2e\u52a9\u5230\u4f60\u5c31\u66f4\u597d\u4e86\uff01<\/span><\/p>\n

\u95ee\u9898\u5185\u5bb9
\n <\/p>\n

\u6211\u7684 mongodb \u6587\u6863\u4e2d\u6709\u4e00\u4e2a objectid \u6570\u7ec4\uff0c\u6211\u60f3\u4f7f\u7528 go\uff08\u7279\u522b\u662f mgo.v2\uff09\u6267\u884c\u67e5\u8be2\uff0c\u7528\u5b83\u4eec\u5f15\u7528\u7684\u6587\u6863\u4e2d\u7684\u6570\u636e\u586b\u5145\u5b83\u4eec\u3002\u4f8b\u5982\uff1a<\/p>\n

{\n  _id: objectid(\"some_id\"),\n  events: [\n    objectid(\"referenced_id_1\"),\n    objectid(\"referenced_id_2\")\n  ]\n}<\/pre>\n
\u6211\u5e0c\u671b\u67e5\u8be2\u8fd4\u56de\u4ee5\u4e0b\u683c\u5f0f\u7684\u6587\u6863\uff1a<\/p>\n
 15536\u200b\u200b6893893 <\/p>\n
\u636e\u6211\u6240\u77e5\uff0c\u6211\u9700\u8981\u4f7f\u7528 $lookup<\/code> \u7136\u540e $unwind<\/code>\uff0c\u4f46\u4f3c\u4e4e\u65e0\u6cd5\u5f04\u6e05\u695a\u3002\u4efb\u4f55\u5e2e\u52a9\u5c06\u975e\u5e38\u611f\u6fc0\uff01\u8c22\u8c22:)<\/p>\n
 <\/p>\n
\u89e3\u51b3\u65b9\u6848<\/h2>\n
 <\/p>\n
\u6211\u76f8\u4fe1\u4f60\u60f3\u505a\u8fd9\u6837\u7684\u4e8b\u60c5\uff1a<\/p>\n
db.getCollection(\"some_collection\").aggregate([\n    { $match: { _id: ObjectId(\"some_id\") } },\n\n     \/\/ match events ids and then replace field \"events\" with the matching results\n    { $lookup: {\n            from: \"referenced_collection\",\n            localField: \"events\",\n            foreignField: \"_id\",\n            as: \"events\"\n    }}\n\n    \/\/ there is no need for an $unwind step here since the expected output requires \"events\" to be an array\n])<\/pre>\n
\u4e0a\u9762\u7684\u67e5\u8be2\u4f7f\u7528\u4e86 $lookup<\/code> \u7684\u7b80\u5316\u7248\u672c\uff0c\u5047\u8bbe\u60a8\u4e0d\u9700\u8981 pre-$project<\/code> \u201c\u4e8b\u4ef6\u201d$lookup<\/code> \u7ed3\u679c\uff0c\u4e5f\u4e0d\u9700\u8981\u4f7f\u7528\u989d\u5916\u7684\u5339\u914d\u952e\u3002\u5982\u679c\u60a8\u786e\u5b9e\u9700\u8981\u8fd9\u4e9b\u4e1c\u897f\uff0c\u6211\u5efa\u8bae\u60a8\u67e5\u770b mongodb \u7684\u6587\u6863\u4ee5\u8fdb\u884c\u5fc5\u8981\u7684\u6539\u8fdb\u3002<\/p>\n
\u4ee5\u4e0a\u5c31\u662f\u300a\u5982\u4f55\u586b\u5145\u5916\u90e8\u5b57\u6bb5 ID \u7684 MongoDB \u6570\u7ec4\uff1f\u300b\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u5173\u4e8e\u7684\u8d44\u6599\u8bf7\u5173\u6ce8\u516c\u4f17\u53f7\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5f53\u524d\u4f4d\u7f6e\uff1a > > ...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-207680","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207680","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=207680"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/207680\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=207680"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=207680"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=207680"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}