{"id":200260,"date":"2025-05-06T12:29:21","date_gmt":"2025-05-06T04:29:21","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200260\/"},"modified":"2025-05-06T12:29:21","modified_gmt":"2025-05-06T04:29:21","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8-sql-%e6%9f%a5%e8%af%a2%e8%8e%b7%e5%8f%96%e6%96%87%e7%ab%a0%e5%8f%8a%e5%85%b6%e5%89%8d-5-%e6%9d%a1%e8%af%84%e8%ae%ba%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200260\/","title":{"rendered":"\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8be2\u83b7\u53d6\u6587\u7ae0\u53ca\u5176\u524d 5 \u6761\u8bc4\u8bba\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8be2\u83b7\u53d6\u6587\u7ae0\u53ca\u5176\u524d 5 \u6761\u8bc4\u8bba\uff1f<\/h1>\n<p>\u600e\u4e48\u5165\u95e8\u6570\u636e\u5e93\u7f16\u7a0b\uff1f\u9700\u8981\u5b66\u4e60\u54ea\u4e9b\u77e5\u8bc6\u70b9\uff1f\u8fd9\u662f\u65b0\u624b\u4eec\u521a\u63a5\u89e6\u7f16\u7a0b\u65f6\u5e38\u89c1\u7684\u95ee\u9898\uff1b\u4e0b\u9762\u4e3b\u673a\u5b9d\u8d1d\u5c31\u6765\u7ed9\u5927\u5bb6\u6574\u7406\u5206\u4eab\u4e00\u4e9b\u77e5\u8bc6\u70b9\uff0c\u5e0c\u671b\u80fd\u591f\u7ed9\u521d\u5b66\u8005\u4e00\u4e9b\u5e2e\u52a9\u3002\u672c\u7bc7\u6587\u7ae0\u5c31\u6765\u4ecb\u7ecd\u300a\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8be2\u83b7\u53d6\u6587\u7ae0\u53ca\u5176\u524d 5 \u6761\u8bc4\u8bba\uff1f\u300b\uff0c\u6d89\u53ca\u5230\uff0c\u6709\u9700\u8981\u7684\u53ef\u4ee5\u6536\u85cf\u4e00\u4e0b<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241030\/17302777606721f18033f06.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>\u901a\u8fc7 sql \u67e5\u8be2\u6587\u7ae0\u53ca\u5176\u524d 5 \u6761\u8bc4\u8bba<\/strong><\/p>\n<p><strong>\u7b80\u4ecb\uff1a<\/strong><\/p>\n<p>\u60a8\u9700\u8981\u67e5\u8be2\u6240\u6709\u6587\u7ae0\u53ca\u5176\u5173\u8054\u7684\u8bc4\u8bba\uff0c\u4f46\u6bcf\u7bc7\u6587\u7ae0\u6700\u591a\u663e\u793a\u524d 5 \u6761\u8bc4\u8bba\u3002\u4f20\u7edf\u7684 left join \u67e5\u8be2\u65e0\u6cd5\u6ee1\u8db3\u6b64\u9650\u5236\u3002\u672c\u6587\u5c06\u63d0\u4f9b\u4e00\u79cd sql \u89e3\u51b3\u65b9\u6cd5\uff0c\u4ee5\u63d0\u53d6\u6240\u9700\u7684\u6570\u636e\u3002<\/p>\n<p><strong>sql \u67e5\u8be2\uff1a<\/strong><\/p>\n<pre>select \n    tmp1.id, tmp1.content, tmp.comment\nfrom\n    (select\n    a.pid, a.comment\n     from\n         `comment` a\n     where\n         5 &amp;gt; (select count(id) from `comment` b where b.pid = a.pid and a.id &amp;gt; b.id)\n     order by\n         a.id desc) tmp\n     join article tmp1 on tmp.pid = tmp1.id<\/pre>\n<p><strong>\u8bf4\u660e\uff1a<\/strong><\/p>\n<ul>\n<li><strong>\u5b50\u67e5\u8be2\uff1a<\/strong>\u6b64\u5b50\u67e5\u8be2\u4ece comment \u8868\u4e2d\u63d0\u53d6\u6bcf\u4e2a\u6587\u7ae0\u7684\u524d 5 \u6761\u8bc4\u8bba\u3002<\/li>\n<li><strong>\u6761\u4ef6\uff1a<\/strong>\u5b50\u67e5\u8be2\u4e2d\u7684 where \u5b50\u53e5\u68c0\u67e5\u6bcf\u4e2a\u8bc4\u8bba\u662f\u5426\u5728\u524d 5 \u6761\u8bc4\u8bba\u4e4b\u5185\u3002<\/li>\n<li><strong>\u964d\u5e8f\u6392\u5e8f\uff1a<\/strong>\u5b50\u67e5\u8be2\u4e2d\u7684 order by \u5b50\u53e5\u5c06\u8bc4\u8bba\u6309\u964d\u5e8f\u6392\u5217\uff0c\u4ee5\u83b7\u5f97\u6700\u65e9\u7684\u8bc4\u8bba\u3002<\/li>\n<li><strong>join\uff1a<\/strong>\u5916\u90e8\u67e5\u8be2\u5c06\u5b50\u67e5\u8be2\u4e0e article \u8868\u8fde\u63a5\uff0c\u4f7f\u7528 pid \u5217\u5339\u914d\u6587\u7ae0\u548c\u8bc4\u8bba\u3002<\/li>\n<\/ul>\n<p><strong>\u7ed3\u679c\uff1a<\/strong><\/p>\n<p>\u6b64\u67e5\u8be2\u5c06\u8fd4\u56de\u4e00\u4e2a\u6570\u636e\u96c6\u7ed3\u6784\uff0c\u5176\u4e2d\u6bcf\u4e2a\u6587\u7ae0\u5305\u542b\u5176\u5185\u5bb9\u548c\u5173\u8054\u7684\u524d 5 \u6761\u8bc4\u8bba\u3002\u8f93\u51fa\u793a\u4f8b\uff1a<\/p>\n<pre>[\n    {\n        \"id\": 1,\n        \"content\": \"\u6587\u7ae0\u5185\u5bb9 1\",\n        \"commentList\": [\n            {\n                \"commentid\": 1,\n                \"comment\": \"\u8bc4\u8bba 1\"\n            },\n            {\n                \"commentid\": 2,\n                \"comment\": \"\u8bc4\u8bba 2\"\n            },\n            {\n                \"commentid\": 3,\n                \"comment\": \"\u8bc4\u8bba 3\"\n            },\n            {\n                \"commentid\": 4,\n                \"comment\": \"\u8bc4\u8bba 4\"\n            },\n            {\n                \"commentid\": 5,\n                \"comment\": \"\u8bc4\u8bba 5\"\n            }\n        ]\n    },\n    \/\/ ...\u5176\u4ed6\u6587\u7ae0\u7684\u6570\u636e\n]<\/pre>\n<p>\u672c\u7bc7\u5173\u4e8e\u300a\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8be2\u83b7\u53d6\u6587\u7ae0\u53ca\u5176\u524d 5 \u6761\u8bc4\u8bba\uff1f\u300b\u7684\u4ecb\u7ecd\u5c31\u5230\u6b64\u7ed3\u675f\u5566\uff0c\u4f46\u662f\u5b66\u65e0\u6b62\u5883\uff0c\u60f3\u8981\u4e86\u89e3\u5b66\u4e60\u66f4\u591a\u5173\u4e8e\u6570\u636e\u5e93\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u8bf7\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u5982\u4f55\u4f7f\u7528 SQL \u67e5\u8be2\u83b7\u53d6\u6587\u7ae0\u53ca&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-200260","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200260","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=200260"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200260\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200260"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200260"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200260"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}