\n\t\u5982\u679c\u9700\u8981\u5305\u542b\u7684\u5b57\u6bb5\u592a\u591a\uff0c\u53ef\u4ee5\u4f7f\u7528 Projection.exclude \u65b9\u6cd5\uff0c\u53cd\u5411\u6392\u9664\u4e00\u4e9b\u5b57\u6bb5\u3002\n<\/p>\n
\r\nexclude("xttblog", "url")<\/pre>\n\n\texclude \u548c include \u65b9\u6cd5\u90fd\u4f1a\u5305\u542b _id \u5b57\u6bb5\uff0c\u4e5f\u5c31\u662f ObjectId \u90fd\u4f1a\u67e5\u8be2\u51fa\u6765\u3002\u90a3\u4e48\u6709\u6ca1\u6709\u529e\u6cd5\u6392\u9664 ObjectId \u5462\uff1f\u7b54\u6848\u5c31\u662f excludeId \u65b9\u6cd5\u3002excludeId() \u65b9\u6cd5\uff0c\u76f8\u5f53\u4e8e exclude("_id")\u3002\n<\/p>\n
\n\t\u5982\u679c\u53ea\u8981\u67e5\u8be2\u7ed3\u679c\u4e2d\u7684\u7b2c\u4e00\u6761\u5bf9\u8c61\uff0c\u53ef\u4ee5\u4f7f\u7528 elemMatch \u65b9\u6cd5\u3002\u5982\uff1a\n<\/p>\n
\r\nelemMatch("orders", Filters.gt("quantity", 3))<\/pre>\n\n\t\u4e0a\u9762\u8fd9\u4e2a\u4f8b\u5b50\u53ea\u4f1a\u8fd4\u56de orders \u6587\u6863\u7684 quantity \u5b57\u6bb5\u5927\u4e8e 3 \u7684\u7b2c\u4e00\u4e2a\u7ed3\u679c\u3002\n<\/p>\n
\n\t\u5982\u679c\u67d0\u4e2a\u5b57\u6bb5\u5bf9\u5e94\u7684\u503c\u662f\u4e00\u4e2a\u6570\u7ec4\u3002\u9700\u8981\u5bf9\u8fd9\u4e2a\u6570\u7ec4\u8fdb\u884c\u5206\u5272\u53d6\u503c\u7684\u8bdd\uff0c\u53ef\u4ee5\u4f7f\u7528 slice \u65b9\u6cd5\u3002\n<\/p>\n
\r\nslice("tags", 7) \/\/\u8fd4\u56de tag \u6570\u7ec4\u7684\u524d 7 \u4e2a\u5143\u7d20\r\nslice("tags", 2, 5) \/\/\u8df3\u8fc7\u6570\u7ec4 tags \u7684\u524d 2 \u4e2a\u5143\u7d20, \u8fd4\u56de\u63a5\u4e0b\u6765\u7684 5 \u4e2a\u5143\u7d20<\/pre>\n\n\tMongoDB \u652f\u6301\u5bf9\u6587\u672c\u5185\u5bb9\u6267\u884c\u6587\u672c\u641c\u7d22\u64cd\u4f5c\uff0c\u5176\u63d0\u4f9b\u4e86\u7d22\u5f15text index\u548c\u67e5\u8be2\u64cd\u4f5c $text \u6765\u5b8c\u6210\u6587\u672c\u641c\u7d22\u529f\u80fd\u3002Projections \u4e2d\u7684 metaTextScore \u65b9\u6cd5\u63d0\u4f9b\u5bf9\u6587\u672c\u7d22\u5f15\u5339\u914d\u5230\u7684\u6570\u636e\u6253\u5206\u3002\u5982\u4e0b\uff1a\n<\/p>\n
\r\ndb.articles.find(\r\n { author: "xyz", $text: { $search: "coffee bake" } },\r\n { score: { $meta: "textScore" } }\r\n).sort( { date: 1, score: { $meta: "textScore" } } )<\/pre>\n\n\t\u4e0a\u9762\u7684\u67e5\u8be2\u4f1a\u641c\u7d22 author \u7b49\u4e8e equals "xyz"\u548c\u7d22\u5f15\u6587\u672c\u5b57\u6bb5\u5305\u542b\u672f\u8bed coffee \u6216 bake \u7684\u6587\u6863 \u3002\u8be5\u64cd\u4f5c\u8fd8\u6307\u5b9a\u4e86\u6309 date \u5347\u5e8f\u6392\u5217\uff0c\u7136\u540e\u964d\u5e8f\u6587\u672c\u641c\u7d22\u5206\u6570\u7684\u6392\u5e8f\u987a\u5e8f\u3002\n<\/p>\n
\n\t\u5982\u679c\u8981\u7ec4\u5408\u591a\u4e2a\u8fd4\u56de\u5b57\u6bb5\uff0c\u53ef\u4ee5\u4f7f\u7528 fields \u65b9\u6cd5\u3002\n<\/p>\n
\r\nfields(include("quantity", "totalAmonut"), excludeId())<\/pre>\n\n\t\u53e6\u5916\u8fd8\u6709\u4e00\u4e2a\u4e0d\u5e38\u7528\u7684\u65b9\u6cd5 computed\uff0c\u5b83\u76f8\u5f53\u4e8e $project \u7684\u7528\u6cd5\u3002\u5177\u4f53\u5927\u5bb6\u53ef\u4ee5\u81ea\u5df1\u53bb\u6478\u7d22\u4e00\u4e0b\uff01<\/p>\n
![\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/](\"https:\/\/saas.51autoparts.cn\/api\/admin\/sys-file\/oss\/file?fileName=84db51f8561e448f9a4fda2eff0811f9.jpg\")
<\/p>
\u6700\u540e\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u4e2a\u4eba\u5fae\u4fe1\u516c\u4f17\u53f7\uff1a\u4e1a\u4f59\u8349\uff08yyucao\uff09\uff01\u53ef\u52a0\u4f5c\u8005\u5fae\u4fe1\u53f7\uff1axttblog2<\/font>\u3002\u5907\u6ce8\uff1a\u201c1\u201d\uff0c\u6dfb\u52a0\u535a\u4e3b\u5fae\u4fe1\u62c9\u4f60\u8fdb\u5fae\u4fe1\u7fa4\u3002\u5907\u6ce8\u9519\u8bef\u4e0d\u4f1a\u540c\u610f\u597d\u53cb\u7533\u8bf7\u3002<\/b>\u518d\u6b21\u611f\u8c22\u60a8\u7684\u5173\u6ce8\uff01\u540e\u7eed\u6709\u7cbe\u5f69\u5185\u5bb9\u4f1a\u7b2c\u4e00\u65f6\u95f4\u53d1\u7ed9\u60a8\uff01\u539f\u521b\u6587\u7ae0\u6295\u7a3f\u8bf7\u53d1\u9001\u81f3532009913@qq.com\u90ae\u7bb1\u3002\u5546\u52a1\u5408\u4f5c\u4e5f\u53ef\u6dfb\u52a0\u4f5c\u8005\u5fae\u4fe1\u8fdb\u884c\u8054\u7cfb\uff01<\/p>\u672c\u6587\u539f\u6587\u51fa\u5904\uff1a\u4e1a\u4f59\u8349<\/a>\uff1a » \u8be6\u89e3 com.mongodb.client.model.Projections \u9650\u5236 MongoDB \u67e5\u8be2\u8fd4\u56de\u5b57\u6bb5\u7528\u6cd5<\/a><\/p>","protected":false},"excerpt":{"rendered":"Projections \u662f MongoDB Java \u9a71\u52a8\u5305\u4e2d\u7684\u4e00\u4e2a\u7c7b\u3002\u5b83\u91cc\u9762\u63d0\u4f9b\u4e86\u975e\u5e38\u591a\u7684\u9759\u6001\u65b9\u6cd5\uff0cProj […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[1776,1774,1578,1775,1773],"class_list":["post-3477","post","type-post","status-publish","format-standard","hentry","category-java","tag-basicdbobject","tag-mongoclient","tag-mongodb","tag-mongoexception","tag-projections"],"_links":{"self":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3477","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3477"}],"version-history":[{"count":1,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3477\/revisions"}],"predecessor-version":[{"id":3478,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3477\/revisions\/3478"}],"wp:attachment":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3477"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3477"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3477"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}