{"id":77912,"date":"2024-10-16T11:16:15","date_gmt":"2024-10-16T03:16:15","guid":{"rendered":"https:\/\/server.hk\/cnblog\/77912\/"},"modified":"2024-10-16T11:16:15","modified_gmt":"2024-10-16T03:16:15","slug":"mysql%e6%8c%87%e4%bb%a4-character_length%ef%bc%88%e5%ad%97%e7%ac%a6%e9%95%b7%e5%ba%a6%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/77912\/","title":{"rendered":"MySQL\u6307\u4ee4: CHARACTER_LENGTH()\uff08\u5b57\u7b26\u9577\u5ea6\uff09"},"content":{"rendered":"<h1 id=\"mysql%e6%8c%87%e4%bb%a4-character_length%ef%bc%88%e5%ad%97%e7%ac%a6%e9%95%b7%e5%ba%a6%ef%bc%89-XWYaowKTpG\">MySQL\u6307\u4ee4: CHARACTER_LENGTH()\uff08\u5b57\u7b26\u9577\u5ea6\uff09<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0cMySQL\u662f\u4e00\u500b\u5ee3\u6cdb\u4f7f\u7528\u7684\u95dc\u806f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u3002\u5b83\u63d0\u4f9b\u4e86\u591a\u7a2e\u529f\u80fd\u4f86\u8655\u7406\u548c\u5206\u6790\u6578\u64da\uff0c\u5176\u4e2d\u4e4b\u4e00\u5c31\u662f\u7528\u65bc\u8a08\u7b97\u5b57\u7b26\u4e32\u9577\u5ea6\u7684\u51fd\u6578\u2014\u2014CHARACTER_LENGTH()\u3002\u9019\u7bc7\u6587\u7ae0\u5c07\u6df1\u5165\u63a2\u8a0eCHARACTER_LENGTH()\u7684\u7528\u6cd5\u3001\u7279\u6027\u53ca\u5176\u5728\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u91cd\u8981\u6027\u3002<\/p>\n<h2 id=\"character_length%e5%87%bd%e6%95%b8%e6%a6%82%e8%bf%b0-XWYaowKTpG\">CHARACTER_LENGTH()\u51fd\u6578\u6982\u8ff0<\/h2>\n<p>CHARACTER_LENGTH()\u51fd\u6578\u7528\u65bc\u8fd4\u56de\u5b57\u7b26\u4e32\u4e2d\u7684\u5b57\u7b26\u6578\u3002\u9019\u500b\u51fd\u6578\u7684\u4e3b\u8981\u7279\u9ede\u662f\u5b83\u8a08\u7b97\u7684\u662f\u5b57\u7b26\u7684\u6578\u91cf\uff0c\u800c\u4e0d\u662f\u5b57\u7bc0\u7684\u6578\u91cf\u3002\u9019\u5728\u8655\u7406\u591a\u5b57\u7bc0\u5b57\u7b26\u96c6\uff08\u5982UTF-8\uff09\u6642\u5c24\u70ba\u91cd\u8981\uff0c\u56e0\u70ba\u4e00\u500b\u5b57\u7b26\u53ef\u80fd\u4f54\u7528\u591a\u500b\u5b57\u7bc0\u3002<\/p>\n<h2 id=\"%e8%aa%9e%e6%b3%95-XWYaowKTpG\">\u8a9e\u6cd5<\/h2>\n<pre><code>CHARACTER_LENGTH(string)<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>string<\/code>\u662f\u8981\u8a08\u7b97\u5b57\u7b26\u9577\u5ea6\u7684\u5b57\u7b26\u4e32\u3002\u8a72\u51fd\u6578\u8fd4\u56de\u4e00\u500b\u6574\u6578\uff0c\u8868\u793a\u5b57\u7b26\u4e32\u4e2d\u7684\u5b57\u7b26\u6578\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8%e7%af%84%e4%be%8b-XWYaowKTpG\">\u4f7f\u7528\u7bc4\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662fCHARACTER_LENGTH()\u51fd\u6578\u7684\u4e00\u4e9b\u4f7f\u7528\u7bc4\u4f8b\uff1a<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b1%ef%bc%9a%e5%9f%ba%e6%9c%ac%e7%94%a8%e6%b3%95-XWYaowKTpG\">\u7bc4\u4f8b1\uff1a\u57fa\u672c\u7528\u6cd5<\/h3>\n<pre><code>SELECT CHARACTER_LENGTH('Hello, World!') AS length;<\/code><\/pre>\n<p>\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u5b57\u7b26\u4e32\u201cHello, World!\u201d\u7684\u5b57\u7b26\u9577\u5ea6\uff0c\u7d50\u679c\u70ba13\u3002<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b2%ef%bc%9a%e8%99%95%e7%90%86%e5%a4%9a%e5%ad%97%e7%af%80%e5%ad%97%e7%ac%a6-XWYaowKTpG\">\u7bc4\u4f8b2\uff1a\u8655\u7406\u591a\u5b57\u7bc0\u5b57\u7b26<\/h3>\n<pre><code>SELECT CHARACTER_LENGTH('\u4f60\u597d\uff0c\u4e16\u754c\uff01') AS length;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u5b57\u7b26\u4e32\u201c\u4f60\u597d\uff0c\u4e16\u754c\uff01\u201d\u5305\u542b6\u500b\u5b57\u7b26\uff0cCHARACTER_LENGTH()\u5c07\u8fd4\u56de6\uff0c\u800c\u4e0d\u662f\u5b57\u7bc0\u6578\u3002<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b3%ef%bc%9a%e8%88%87%e5%85%b6%e4%bb%96%e5%87%bd%e6%95%b8%e7%b5%90%e5%90%88%e4%bd%bf%e7%94%a8-XWYaowKTpG\">\u7bc4\u4f8b3\uff1a\u8207\u5176\u4ed6\u51fd\u6578\u7d50\u5408\u4f7f\u7528<\/h3>\n<p>CHARACTER_LENGTH()\u51fd\u6578\u53ef\u4ee5\u8207\u5176\u4ed6\u5b57\u7b26\u4e32\u51fd\u6578\u7d50\u5408\u4f7f\u7528\uff0c\u4ee5\u9032\u884c\u66f4\u8907\u96dc\u7684\u67e5\u8a62\u3002\u4f8b\u5982\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528\u5b83\u4f86\u904e\u6ffe\u5b57\u7b26\u9577\u5ea6\u5927\u65bc\u7279\u5b9a\u503c\u7684\u8a18\u9304\uff1a<\/p>\n<pre><code>SELECT name FROM users WHERE CHARACTER_LENGTH(name) &gt; 5;<\/code><\/pre>\n<p>\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u540d\u5b57\u9577\u5ea6\u5927\u65bc5\u500b\u5b57\u7b26\u7684\u7528\u6236\u3002<\/p>\n<h2 id=\"character_length%e7%9a%84%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-XWYaowKTpG\">CHARACTER_LENGTH()\u7684\u61c9\u7528\u5834\u666f<\/h2>\n<p>CHARACTER_LENGTH()\u51fd\u6578\u5728\u591a\u7a2e\u5834\u666f\u4e2d\u90fd\u975e\u5e38\u6709\u7528\uff0c\u7279\u5225\u662f\u5728\u4ee5\u4e0b\u60c5\u6cc1\u4e0b\uff1a<\/p>\n<ul>\n<li><strong>\u6578\u64da\u9a57\u8b49\uff1a<\/strong>\u5728\u7528\u6236\u8a3b\u518a\u6216\u6578\u64da\u8f38\u5165\u6642\uff0c\u53ef\u4ee5\u4f7f\u7528CHARACTER_LENGTH()\u4f86\u78ba\u4fdd\u8f38\u5165\u7684\u6578\u64da\u7b26\u5408\u7279\u5b9a\u7684\u9577\u5ea6\u8981\u6c42\u3002<\/li>\n<li><strong>\u5831\u544a\u751f\u6210\uff1a<\/strong>\u5728\u751f\u6210\u5831\u544a\u6642\uff0c\u53ef\u80fd\u9700\u8981\u8a08\u7b97\u67d0\u4e9b\u5b57\u6bb5\u7684\u5b57\u7b26\u9577\u5ea6\uff0c\u4ee5\u4fbf\u9032\u884c\u683c\u5f0f\u5316\u6216\u986f\u793a\u3002<\/li>\n<li><strong>\u6578\u64da\u6e05\u7406\uff1a<\/strong>\u5728\u6578\u64da\u6e05\u7406\u904e\u7a0b\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528CHARACTER_LENGTH()\u4f86\u8b58\u5225\u548c\u8655\u7406\u7570\u5e38\u9577\u5ea6\u7684\u6578\u64da\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-XWYaowKTpG\">\u7e3d\u7d50<\/h2>\n<p>CHARACTER_LENGTH()\u51fd\u6578\u662fMySQL\u4e2d\u4e00\u500b\u975e\u5e38\u5be6\u7528\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u6709\u6548\u5730\u8655\u7406\u548c\u5206\u6790\u5b57\u7b26\u4e32\u6578\u64da\u3002\u7121\u8ad6\u662f\u5728\u6578\u64da\u9a57\u8b49\u3001\u5831\u544a\u751f\u6210\u9084\u662f\u6578\u64da\u6e05\u7406\u4e2d\uff0c\u9019\u500b\u51fd\u6578\u90fd\u80fd\u767c\u63ee\u91cd\u8981\u4f5c\u7528\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u4f86\u90e8\u7f72\u60a8\u7684MySQL\u6578\u64da\u5eab\uff0c\u4eab\u53d7\u7a69\u5b9a\u548c\u5feb\u901f\u7684\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u7684CHARACTER_LENGTH()\u51fd\u6570\uff0c\u83b7\u53d6\u5b57\u7b26\u4e32\u7684\u5b57\u7b26\u957f\u5ea6\uff0c\u9002\u7528\u4e8e\u591a\u79cd\u5b57\u7b26\u96c6\uff0c\u786e\u4fdd\u6570\u636e\u5904\u7406\u7684\u51c6\u786e\u6027\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-77912","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/77912","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=77912"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/77912\/revisions"}],"predecessor-version":[{"id":77913,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/77912\/revisions\/77913"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=77912"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=77912"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=77912"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}