{"id":81414,"date":"2024-10-16T15:36:19","date_gmt":"2024-10-16T07:36:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/81414\/"},"modified":"2024-10-16T15:36:19","modified_gmt":"2024-10-16T07:36:19","slug":"null-redis%e6%9f%a5%e8%a9%a2%e7%b5%90%e6%9e%9c%e6%9c%aa%e6%9e%9c-null%e5%80%bc%e8%bf%94%e5%9b%9e%ef%bc%88redis%e6%9f%a5%e4%b8%8d%e5%88%b0%e8%bf%94%e5%9b%9e%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/81414\/","title":{"rendered":"NULL Redis\u67e5\u8a62\u7d50\u679c\u672a\u679c Null\u503c\u8fd4\u56de\uff08Redis\u67e5\u4e0d\u5230\u8fd4\u56de\uff09"},"content":{"rendered":"<h1 id=\"null-redis%e6%9f%a5%e8%a9%a2%e7%b5%90%e6%9e%9c%e6%9c%aa%e6%9e%9c-null%e5%80%bc%e8%bf%94%e5%9b%9e%ef%bc%88redis%e6%9f%a5%e4%b8%8d%e5%88%b0%e8%bf%94%e5%9b%9e%ef%bc%89-grKLALgtIS\">NULL Redis\u67e5\u8a62\u7d50\u679c\u672a\u679c Null\u503c\u8fd4\u56de\uff08Redis\u67e5\u4e0d\u5230\u8fd4\u56de\uff09<\/h1>\n<p>\u5728\u7576\u4eca\u7684\u6578\u64da\u9a45\u52d5\u4e16\u754c\u4e2d\uff0cRedis\u4f5c\u70ba\u4e00\u7a2e\u9ad8\u6548\u7684\u9375\u503c\u5b58\u5132\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u5404\u7a2e\u61c9\u7528\u7a0b\u5e8f\u4e2d\u3002\u7121\u8ad6\u662f\u7528\u65bc\u7de9\u5b58\u3001\u6d88\u606f\u968a\u5217\u9084\u662f\u6578\u64da\u6301\u4e45\u5316\uff0cRedis\u90fd\u80fd\u63d0\u4f9b\u5353\u8d8a\u7684\u6027\u80fd\u3002\u7136\u800c\uff0c\u5728\u4f7f\u7528Redis\u9032\u884c\u67e5\u8a62\u6642\uff0c\u958b\u767c\u8005\u7d93\u5e38\u6703\u9047\u5230\u67e5\u8a62\u7d50\u679c\u70baNULL\u7684\u60c5\u6cc1\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eRedis\u67e5\u8a62\u7d50\u679c\u672a\u679c\u7684\u539f\u56e0\u53ca\u5176\u8655\u7406\u65b9\u5f0f\u3002<\/p>\n<h2 id=\"redis%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-grKLALgtIS\">Redis\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>Redis\u662f\u4e00\u7a2e\u958b\u6e90\u7684\u9ad8\u6027\u80fd\u9375\u503c\u6578\u64da\u5eab\uff0c\u652f\u6301\u591a\u7a2e\u6578\u64da\u7d50\u69cb\uff0c\u5982\u5b57\u7b26\u4e32\u3001\u54c8\u5e0c\u3001\u5217\u8868\u3001\u96c6\u5408\u7b49\u3002\u5b83\u7684\u9ad8\u6548\u6027\u4e3b\u8981\u4f86\u81ea\u65bc\u5176\u5167\u5b58\u5b58\u5132\u7684\u7279\u6027\uff0c\u4e26\u4e14\u652f\u6301\u6301\u4e45\u5316\u9078\u9805\uff0c\u80fd\u5920\u5c07\u6578\u64da\u4fdd\u5b58\u5230\u78c1\u789f\u4e2d\u3002<\/p>\n<h2 id=\"%e6%9f%a5%e8%a9%a2%e7%b5%90%e6%9e%9c%e7%82%banull%e7%9a%84%e5%8e%9f%e5%9b%a0-grKLALgtIS\">\u67e5\u8a62\u7d50\u679c\u70baNULL\u7684\u539f\u56e0<\/h2>\n<p>\u5728\u4f7f\u7528Redis\u9032\u884c\u67e5\u8a62\u6642\uff0c\u8fd4\u56deNULL\u7684\u60c5\u6cc1\u901a\u5e38\u6709\u4ee5\u4e0b\u5e7e\u7a2e\u539f\u56e0\uff1a<\/p>\n<ul>\n<li><strong>\u9375\u4e0d\u5b58\u5728\uff1a<\/strong>\u7576\u67e5\u8a62\u7684\u9375\u5728Redis\u4e2d\u4e0d\u5b58\u5728\u6642\uff0cRedis\u6703\u8fd4\u56deNULL\u3002\u4f8b\u5982\uff0c\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\u67e5\u8a62\u4e00\u500b\u4e0d\u5b58\u5728\u7684\u9375\uff1a<\/li>\n<pre><code>GET nonexistent_key<\/code><\/pre>\n<p>\u9019\u5c07\u8fd4\u56deNULL\uff0c\u8868\u793a\u8a72\u9375\u672a\u88ab\u627e\u5230\u3002<\/p>\n<li><strong>\u6578\u64da\u904e\u671f\uff1a<\/strong>Redis\u652f\u6301\u8a2d\u7f6e\u9375\u7684\u904e\u671f\u6642\u9593\u3002\u5982\u679c\u4e00\u500b\u9375\u5728\u67e5\u8a62\u4e4b\u524d\u5df2\u7d93\u904e\u671f\uff0c\u5247\u67e5\u8a62\u7d50\u679c\u4e5f\u6703\u8fd4\u56deNULL\u3002\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\u8a2d\u7f6e\u904e\u671f\u6642\u9593\uff1a<\/li>\n<pre><code>SETEX mykey 10 \"value\"<\/code><\/pre>\n<p>\u9019\u5c07\u572810\u79d2\u5f8c\u4f7fmykey\u904e\u671f\u3002<\/p>\n<li><strong>\u6578\u64da\u985e\u578b\u4e0d\u5339\u914d\uff1a<\/strong>\u5982\u679c\u67e5\u8a62\u7684\u9375\u5b58\u5728\uff0c\u4f46\u5176\u6578\u64da\u985e\u578b\u8207\u67e5\u8a62\u64cd\u4f5c\u4e0d\u5339\u914d\uff0c\u4e5f\u53ef\u80fd\u5c0e\u81f4NULL\u8fd4\u56de\u3002\u4f8b\u5982\uff0c\u5c0d\u4e00\u500b\u54c8\u5e0c\u985e\u578b\u7684\u9375\u4f7f\u7528\u5b57\u7b26\u4e32\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e8%99%95%e7%90%86null%e8%bf%94%e5%9b%9e-grKLALgtIS\">\u5982\u4f55\u8655\u7406NULL\u8fd4\u56de<\/h2>\n<p>\u7576Redis\u67e5\u8a62\u8fd4\u56deNULL\u6642\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u63a1\u53d6\u4ee5\u4e0b\u5e7e\u7a2e\u7b56\u7565\u4f86\u8655\u7406\uff1a<\/p>\n<ul>\n<li><strong>\u6aa2\u67e5\u9375\u7684\u5b58\u5728\u6027\uff1a<\/strong>\u5728\u9032\u884c\u67e5\u8a62\u4e4b\u524d\uff0c\u53ef\u4ee5\u4f7f\u7528EXISTS\u547d\u4ee4\u4f86\u6aa2\u67e5\u9375\u662f\u5426\u5b58\u5728\uff1a<\/li>\n<pre><code>EXISTS mykey<\/code><\/pre>\n<p>\u5982\u679c\u8fd4\u56de1\uff0c\u5247\u9375\u5b58\u5728\uff1b\u5982\u679c\u8fd4\u56de0\uff0c\u5247\u9375\u4e0d\u5b58\u5728\u3002<\/p>\n<li><strong>\u8a2d\u7f6e\u9ed8\u8a8d\u503c\uff1a<\/strong>\u5728\u67e5\u8a62\u6642\uff0c\u53ef\u4ee5\u8003\u616e\u8a2d\u7f6e\u4e00\u500b\u9ed8\u8a8d\u503c\uff0c\u4ee5\u4fbf\u5728\u67e5\u8a62\u7d50\u679c\u70baNULL\u6642\u4f7f\u7528\u3002\u4f8b\u5982\uff1a<\/li>\n<pre><code>value = GET mykey\nif value is None:\n    value = \"default_value\"<\/code><\/pre>\n<p>\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u56e0\u70baNULL\u8fd4\u56de\u800c\u5c0e\u81f4\u7684\u932f\u8aa4\u3002<\/p>\n<li><strong>\u4f7f\u7528\u904e\u671f\u7b56\u7565\uff1a<\/strong>\u5982\u679c\u6578\u64da\u7d93\u5e38\u904e\u671f\uff0c\u53ef\u4ee5\u8003\u616e\u4f7f\u7528\u6301\u4e45\u5316\u7b56\u7565\uff0c\u5c07\u91cd\u8981\u6578\u64da\u5b9a\u671f\u4fdd\u5b58\u5230\u78c1\u789f\u4e2d\uff0c\u4ee5\u6e1b\u5c11\u6578\u64da\u4e1f\u5931\u7684\u98a8\u96aa\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-grKLALgtIS\">\u7d50\u8ad6<\/h2>\n<p>\u5728\u4f7f\u7528Redis\u6642\uff0c\u67e5\u8a62\u7d50\u679c\u70baNULL\u662f\u4e00\u500b\u5e38\u898b\u7684\u60c5\u6cc1\uff0c\u4e86\u89e3\u5176\u539f\u56e0\u53ca\u8655\u7406\u65b9\u5f0f\u5c0d\u65bc\u958b\u767c\u8005\u4f86\u8aaa\u81f3\u95dc\u91cd\u8981\u3002\u901a\u904e\u6aa2\u67e5\u9375\u7684\u5b58\u5728\u6027\u3001\u8a2d\u7f6e\u9ed8\u8a8d\u503c\u4ee5\u53ca\u5408\u7406\u4f7f\u7528\u904e\u671f\u7b56\u7565\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u61c9\u5c0d\u9019\u4e00\u554f\u984c\u3002\u96a8\u8457Redis\u5728\u5404\u7a2e\u61c9\u7528\u4e2d\u7684\u5ee3\u6cdb\u61c9\u7528\uff0c\u638c\u63e1\u9019\u4e9b\u6280\u5de7\u5c07\u6709\u52a9\u65bc\u63d0\u5347\u958b\u767c\u6548\u7387\u548c\u7cfb\u7d71\u7a69\u5b9a\u6027\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u95dc\u65bc<code><a href=\"https:\/\/server.hk\">VPS<\/a><\/code>\u548c<code><a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a><\/code>\u7684\u8cc7\u8a0a\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3Redis\u67e5\u8a62\u7d50\u679c\u70baNULL\u7684\u60c5\u6cc1\uff0c\u63a2\u8a0e\u67e5\u4e0d\u5230\u6578\u64da\u6642\u7684Null\u503c\u8fd4\u56de\u53ca\u5176\u5f71\u97ff\u3002<\/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-81414","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/81414","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=81414"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/81414\/revisions"}],"predecessor-version":[{"id":81415,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/81414\/revisions\/81415"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=81414"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=81414"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=81414"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}