{"id":78914,"date":"2024-10-16T12:29:17","date_gmt":"2024-10-16T04:29:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/78914\/"},"modified":"2024-10-16T12:29:17","modified_gmt":"2024-10-16T04:29:17","slug":"mysql%e6%8c%87%e4%bb%a4-length%ef%bc%88%e5%ad%97%e7%ac%a6%e4%b8%b2%e9%95%b7%e5%ba%a6%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/78914\/","title":{"rendered":"MySQL\u6307\u4ee4: LENGTH()\uff08\u5b57\u7b26\u4e32\u9577\u5ea6\uff09"},"content":{"rendered":"<h1 id=\"mysql%e6%8c%87%e4%bb%a4-length%ef%bc%88%e5%ad%97%e7%ac%a6%e4%b8%b2%e9%95%b7%e5%ba%a6%ef%bc%89-nDHAkhGfGu\">MySQL\u6307\u4ee4: LENGTH()\uff08\u5b57\u7b26\u4e32\u9577\u5ea6\uff09<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\u3002MySQL\u63d0\u4f9b\u4e86\u591a\u7a2e\u51fd\u6578\u4f86\u8655\u7406\u5b57\u7b26\u4e32\uff0c\u5176\u4e2d\u4e4b\u4e00\u5c31\u662fLENGTH()\u51fd\u6578\u3002\u9019\u7bc7\u6587\u7ae0\u5c07\u6df1\u5165\u63a2\u8a0eLENGTH()\u51fd\u6578\u7684\u7528\u6cd5\u3001\u7279\u6027\u53ca\u5176\u5728\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u91cd\u8981\u6027\u3002<\/p>\n<h2 id=\"length%e5%87%bd%e6%95%b8%e6%a6%82%e8%bf%b0-nDHAkhGfGu\">LENGTH()\u51fd\u6578\u6982\u8ff0<\/h2>\n<p>LENGTH()\u51fd\u6578\u7528\u65bc\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u5b57\u7bc0\u9577\u5ea6\u3002\u9019\u610f\u5473\u8457\u5b83\u8a08\u7b97\u7684\u662f\u5b57\u7b26\u4e32\u4e2d\u6240\u4f54\u7528\u7684\u5b57\u7bc0\u6578\uff0c\u800c\u4e0d\u662f\u5b57\u7b26\u6578\u3002\u9019\u4e00\u9ede\u5728\u8655\u7406\u591a\u5b57\u7bc0\u5b57\u7b26\u96c6\uff08\u5982UTF-8\uff09\u6642\u5c24\u70ba\u91cd\u8981\u3002<\/p>\n<h3 id=\"%e8%aa%9e%e6%b3%95-nDHAkhGfGu\">\u8a9e\u6cd5<\/h3>\n<pre><code>LENGTH(string)<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>string<\/code>\u662f\u4f60\u60f3\u8981\u8a08\u7b97\u9577\u5ea6\u7684\u5b57\u7b26\u4e32\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8%e7%a4%ba%e4%be%8b-nDHAkhGfGu\">\u4f7f\u7528\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u4e9b\u4f7f\u7528LENGTH()\u51fd\u6578\u7684\u793a\u4f8b\uff1a<\/p>\n<h3 id=\"%e5%9f%ba%e6%9c%ac%e7%a4%ba%e4%be%8b-nDHAkhGfGu\">\u57fa\u672c\u793a\u4f8b<\/h3>\n<pre><code>SELECT LENGTH('Hello, World!') AS Length;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u5b57\u7b26\u4e32\u201cHello, World!\u201d\u7684\u5b57\u7bc0\u9577\u5ea6\uff0c\u7d50\u679c\u70ba13\u3002<\/p>\n<h3 id=\"%e5%a4%9a%e5%ad%97%e7%af%80%e5%ad%97%e7%ac%a6%e7%a4%ba%e4%be%8b-nDHAkhGfGu\">\u591a\u5b57\u7bc0\u5b57\u7b26\u793a\u4f8b<\/h3>\n<p>\u5728\u4f7f\u7528UTF-8\u5b57\u7b26\u96c6\u6642\uff0c\u67d0\u4e9b\u5b57\u7b26\u53ef\u80fd\u4f54\u7528\u591a\u500b\u5b57\u7bc0\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT LENGTH('\u4f60\u597d') AS Length;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u201c\u4f60\u597d\u201d\u7684\u5b57\u7bc0\u9577\u5ea6\uff0c\u7d50\u679c\u70ba6\uff0c\u56e0\u70ba\u6bcf\u500b\u6f22\u5b57\u5728UTF-8\u4e2d\u4f54\u75283\u500b\u5b57\u7bc0\u3002<\/p>\n<h2 id=\"length%e8%88%87char_length%e7%9a%84%e5%8d%80%e5%88%a5-nDHAkhGfGu\">LENGTH()\u8207CHAR_LENGTH()\u7684\u5340\u5225<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c\u9664\u4e86LENGTH()\u51fd\u6578\uff0c\u9084\u6709\u4e00\u500b\u540d\u70baCHAR_LENGTH()\u7684\u51fd\u6578\u3002\u9019\u5169\u8005\u7684\u4e3b\u8981\u5340\u5225\u5728\u65bc\uff1a<\/p>\n<ul>\n<li><strong>LENGTH()<\/strong>\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u5b57\u7bc0\u9577\u5ea6\u3002<\/li>\n<li><strong>CHAR_LENGTH()<\/strong>\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u5b57\u7b26\u6578\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT LENGTH('\u4f60\u597d') AS ByteLength, CHAR_LENGTH('\u4f60\u597d') AS CharLength;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u5b57\u7bc0\u9577\u5ea6\u70ba6\uff0c\u5b57\u7b26\u6578\u70ba2\u3002<\/p>\n<h2 id=\"length%e5%87%bd%e6%95%b8%e7%9a%84%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-nDHAkhGfGu\">LENGTH()\u51fd\u6578\u7684\u61c9\u7528\u5834\u666f<\/h2>\n<p>LENGTH()\u51fd\u6578\u5728\u591a\u7a2e\u5834\u666f\u4e2d\u90fd\u975e\u5e38\u6709\u7528\uff0c\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li><strong>\u6578\u64da\u9a57\u8b49<\/strong>\uff1a\u5728\u63d2\u5165\u6578\u64da\u4e4b\u524d\uff0c\u53ef\u4ee5\u4f7f\u7528LENGTH()\u6aa2\u67e5\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\uff0c\u4ee5\u78ba\u4fdd\u5176\u7b26\u5408\u9810\u671f\u7684\u683c\u5f0f\u3002<\/li>\n<li><strong>\u6578\u64da\u6e05\u7406<\/strong>\uff1a\u5728\u8655\u7406\u7528\u6236\u8f38\u5165\u6642\uff0c\u53ef\u4ee5\u904e\u6ffe\u6389\u904e\u9577\u7684\u5b57\u7b26\u4e32\uff0c\u4ee5\u9632\u6b62\u6578\u64da\u5eab\u6ea2\u51fa\u6216\u6027\u80fd\u554f\u984c\u3002<\/li>\n<li><strong>\u5831\u544a\u751f\u6210<\/strong>\uff1a\u5728\u751f\u6210\u5831\u544a\u6642\uff0c\u53ef\u4ee5\u4f7f\u7528LENGTH()\u4f86\u5206\u6790\u6578\u64da\u7684\u7279\u5fb5\uff0c\u4f8b\u5982\u627e\u51fa\u6700\u9577\u6216\u6700\u77ed\u7684\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-nDHAkhGfGu\">\u7e3d\u7d50<\/h2>\n<p>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\u5b57\u7b26\u4e32\u9577\u5ea6\u7684\u554f\u984c\u3002\u7121\u8ad6\u662f\u5728\u6578\u64da\u9a57\u8b49\u3001\u6578\u64da\u6e05\u7406\u9084\u662f\u5831\u544a\u751f\u6210\u4e2d\uff0cLENGTH()\u90fd\u80fd\u767c\u63ee\u91cd\u8981\u4f5c\u7528\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u7ba1\u7406\u6578\u64da\u7684\u7528\u6236\u4f86\u8aaa\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u65b9\u6848\u53ef\u4ee5\u63d0\u4f9b\u66f4\u597d\u7684\u6027\u80fd\u548c\u7a69\u5b9a\u6027\uff0c\u9032\u4e00\u6b65\u63d0\u5347\u6578\u64da\u5eab\u64cd\u4f5c\u7684\u6548\u7387\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u6307\u4ee4LENGTH()\uff0c\u7528\u65bc\u8a08\u7b97\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\uff0c\u5e6b\u52a9\u512a\u5316\u6578\u64da\u5eab\u67e5\u8a62\u548c\u6578\u64da\u8655\u7406\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-78914","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78914","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=78914"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78914\/revisions"}],"predecessor-version":[{"id":78915,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78914\/revisions\/78915"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=78914"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=78914"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=78914"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}