{"id":159955,"date":"2024-11-03T19:04:20","date_gmt":"2024-11-03T11:04:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/159955\/"},"modified":"2024-11-03T19:04:21","modified_gmt":"2024-11-03T11:04:21","slug":"mongodb-%e6%95%99%e7%a8%8b%ef%bc%9amongodb-map-reduce","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/159955\/","title":{"rendered":"MongoDB \u6559\u7a0b\uff1aMongoDB Map Reduce"},"content":{"rendered":"<h1 id=\"mongodb-%e6%95%99%e7%a8%8b%ef%bc%9amongodb-map-reduce-MpghdUOIXD\">MongoDB \u6559\u7a0b\uff1aMongoDB Map Reduce<\/h1>\n<p>\u5728\u5927\u6578\u64da\u8655\u7406\u7684\u4e16\u754c\u4e2d\uff0cMongoDB \u662f\u4e00\u500b\u975e\u5e38\u53d7\u6b61\u8fce\u7684 NoSQL \u6578\u64da\u5eab\u3002\u5b83\u7684\u9748\u6d3b\u6027\u548c\u53ef\u64f4\u5c55\u6027\u4f7f\u5176\u6210\u70ba\u8a31\u591a\u61c9\u7528\u7a0b\u5e8f\u7684\u9996\u9078\u3002MongoDB \u63d0\u4f9b\u4e86\u591a\u7a2e\u6578\u64da\u8655\u7406\u65b9\u6cd5\uff0c\u5176\u4e2d\u4e4b\u4e00\u5c31\u662f Map Reduce\u3002\u9019\u7bc7\u6587\u7ae0\u5c07\u6df1\u5165\u63a2\u8a0e MongoDB \u7684 Map Reduce \u6a5f\u5236\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af-map-reduce%ef%bc%9f-MpghdUOIXD\">\u4ec0\u9ebc\u662f Map Reduce\uff1f<\/h2>\n<p>Map Reduce \u662f\u4e00\u7a2e\u7de8\u7a0b\u6a21\u578b\uff0c\u7528\u65bc\u8655\u7406\u548c\u751f\u6210\u5927\u6578\u64da\u96c6\u3002\u5b83\u7531\u5169\u500b\u4e3b\u8981\u6b65\u9a5f\u7d44\u6210\uff1aMap \u548c Reduce\u3002Map \u6b65\u9a5f\u5c07\u6578\u64da\u96c6\u4e2d\u7684\u6bcf\u500b\u5143\u7d20\u6620\u5c04\u5230\u4e00\u500b\u9375\u503c\u5c0d\uff0c\u800c Reduce \u6b65\u9a5f\u5247\u5c07\u9019\u4e9b\u9375\u503c\u5c0d\u9032\u884c\u805a\u5408\u548c\u8a08\u7b97\u3002<\/p>\n<h2 id=\"mongodb-%e4%b8%ad%e7%9a%84-map-reduce-MpghdUOIXD\">MongoDB \u4e2d\u7684 Map Reduce<\/h2>\n<p>\u5728 MongoDB \u4e2d\uff0cMap Reduce \u662f\u4e00\u7a2e\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u7528\u4f86\u9032\u884c\u8907\u96dc\u7684\u67e5\u8a62\u548c\u6578\u64da\u5206\u6790\u3002\u5b83\u5141\u8a31\u7528\u6236\u5728\u6578\u64da\u5eab\u4e2d\u57f7\u884c\u81ea\u5b9a\u7fa9\u7684 JavaScript \u51fd\u6578\u4f86\u8655\u7406\u6578\u64da\u3002\u9019\u4f7f\u5f97 Map Reduce \u7279\u5225\u9069\u5408\u65bc\u9700\u8981\u9032\u884c\u5927\u91cf\u8a08\u7b97\u7684\u60c5\u6cc1\u3002<\/p>\n<h3 id=\"map-reduce-%e7%9a%84%e5%9f%ba%e6%9c%ac%e7%b5%90%e6%a7%8b-MpghdUOIXD\">Map Reduce \u7684\u57fa\u672c\u7d50\u69cb<\/h3>\n<p>\u5728 MongoDB \u4e2d\uff0cMap Reduce \u7684\u57fa\u672c\u7d50\u69cb\u5982\u4e0b\uff1a<\/p>\n<pre><code>\ndb.collection.mapReduce(\n   mapFunction,\n   reduceFunction,\n   { out: \"outputCollection\" }\n)\n<\/code><\/pre>\n<p>\u5176\u4e2d\uff0c<code>mapFunction<\/code> \u662f\u7528\u4f86\u8655\u7406\u6bcf\u500b\u6587\u6a94\u7684\u51fd\u6578\uff0c<code>reduceFunction<\/code> \u5247\u7528\u4f86\u805a\u5408\u7d50\u679c\u3002<code>out<\/code> \u53c3\u6578\u6307\u5b9a\u4e86\u8f38\u51fa\u7d50\u679c\u7684\u96c6\u5408\u3002<\/p>\n<h3 id=\"%e7%a4%ba%e4%be%8b%ef%bc%9a%e8%a8%88%e7%ae%97%e6%af%8f%e5%80%8b%e7%94%a8%e6%88%b6%e7%9a%84%e8%a8%82%e5%96%ae%e7%b8%bd%e6%95%b8-MpghdUOIXD\">\u793a\u4f8b\uff1a\u8a08\u7b97\u6bcf\u500b\u7528\u6236\u7684\u8a02\u55ae\u7e3d\u6578<\/h3>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>orders<\/code> \u7684\u96c6\u5408\uff0c\u5176\u4e2d\u5305\u542b\u7528\u6236\u7684\u8a02\u55ae\u4fe1\u606f\u3002\u6bcf\u500b\u6587\u6a94\u7684\u7d50\u69cb\u5982\u4e0b\uff1a<\/p>\n<pre><code>\n{\n   \"_id\": ObjectId(\"...\"),\n   \"userId\": \"user1\",\n   \"amount\": 100\n}\n<\/code><\/pre>\n<p>\u6211\u5011\u5e0c\u671b\u8a08\u7b97\u6bcf\u500b\u7528\u6236\u7684\u8a02\u55ae\u7e3d\u6578\u3002\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u7684 Map Reduce \u4ee3\u78bc\uff1a<\/p>\n<pre><code>\nvar mapFunction = function() {\n   emit(this.userId, this.amount);\n};\n\nvar reduceFunction = function(keyUserId, values) {\n   return Array.sum(values);\n};\n\ndb.orders.mapReduce(\n   mapFunction,\n   reduceFunction,\n   { out: \"totalOrders\" }\n);\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>mapFunction<\/code> \u5c07\u6bcf\u500b\u8a02\u55ae\u7684 <code>userId<\/code> \u548c <code>amount<\/code> \u6620\u5c04\u70ba\u9375\u503c\u5c0d\uff0c\u800c <code>reduceFunction<\/code> \u5247\u8a08\u7b97\u6bcf\u500b\u7528\u6236\u7684\u8a02\u55ae\u7e3d\u984d\u3002\u6700\u7d42\u7d50\u679c\u5c07\u5b58\u5132\u5728\u540d\u70ba <code>totalOrders<\/code> \u7684\u96c6\u5408\u4e2d\u3002<\/p>\n<h2 id=\"map-reduce-%e7%9a%84%e5%84%aa%e7%bc%ba%e9%bb%9e-MpghdUOIXD\">Map Reduce \u7684\u512a\u7f3a\u9ede<\/h2>\n<h3 id=\"%e5%84%aa%e9%bb%9e-MpghdUOIXD\">\u512a\u9ede<\/h3>\n<ul>\n<li>\u9748\u6d3b\u6027\uff1a\u7528\u6236\u53ef\u4ee5\u81ea\u5b9a\u7fa9 Map \u548c Reduce \u51fd\u6578\uff0c\u4ee5\u6eff\u8db3\u7279\u5b9a\u9700\u6c42\u3002<\/li>\n<li>\u9069\u7528\u65bc\u5927\u6578\u64da\u96c6\uff1aMap Reduce \u53ef\u4ee5\u8655\u7406\u5927\u91cf\u6578\u64da\uff0c\u9069\u5408\u9032\u884c\u8907\u96dc\u7684\u8a08\u7b97\u3002<\/li>\n<\/ul>\n<h3 id=\"%e7%bc%ba%e9%bb%9e-MpghdUOIXD\">\u7f3a\u9ede<\/h3>\n<ul>\n<li>\u6027\u80fd\uff1a\u5c0d\u65bc\u5c0f\u578b\u6578\u64da\u96c6\uff0cMap Reduce \u53ef\u80fd\u6bd4\u5176\u4ed6\u67e5\u8a62\u65b9\u6cd5\u66f4\u6162\u3002<\/li>\n<li>\u8907\u96dc\u6027\uff1a\u9700\u8981\u7de8\u5beb JavaScript \u51fd\u6578\uff0c\u5c0d\u65bc\u4e0d\u719f\u6089\u7de8\u7a0b\u7684\u7528\u6236\u4f86\u8aaa\u53ef\u80fd\u8f03\u70ba\u56f0\u96e3\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-MpghdUOIXD\">\u7d50\u8ad6<\/h2>\n<p>MongoDB \u7684 Map Reduce \u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u9069\u5408\u7528\u65bc\u8655\u7406\u548c\u5206\u6790\u5927\u6578\u64da\u96c6\u3002\u901a\u904e\u81ea\u5b9a\u7fa9\u7684 Map \u548c Reduce \u51fd\u6578\uff0c\u7528\u6236\u53ef\u4ee5\u9748\u6d3b\u5730\u9032\u884c\u6578\u64da\u8a08\u7b97\u548c\u805a\u5408\u3002\u5118\u7ba1\u5b83\u6709\u4e00\u4e9b\u6027\u80fd\u548c\u8907\u96dc\u6027\u4e0a\u7684\u7f3a\u9ede\uff0c\u4f46\u5728\u8a31\u591a\u60c5\u6cc1\u4e0b\uff0cMap Reduce \u4ecd\u7136\u662f\u4e00\u500b\u975e\u5e38\u6709\u7528\u7684\u9078\u64c7\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u904b\u884c MongoDB\uff0cServer.HK \u63d0\u4f9b\u4e86\u591a\u7a2e\u9078\u64c7\uff0c\u9069\u5408\u5404\u7a2e\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u9084\u662f\u5176\u4ed6\u5730\u5340\u7684\u670d\u52d9\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Learn how to use MongoDB Map Reduce for efficient data processing and analysis in this comprehensive tutorial. Unlock powerful aggregation techniques today!<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-159955","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/159955","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"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=159955"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/159955\/revisions"}],"predecessor-version":[{"id":159956,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/159955\/revisions\/159956"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=159955"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=159955"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=159955"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}