{"id":80762,"date":"2024-10-16T14:42:16","date_gmt":"2024-10-16T06:42:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/80762\/"},"modified":"2024-10-16T14:42:16","modified_gmt":"2024-10-16T06:42:16","slug":"mysql%e5%ad%97%e7%ac%a6%e4%b8%b2%e8%99%95%e7%90%86","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/80762\/","title":{"rendered":"MySQL\u5b57\u7b26\u4e32\u8655\u7406"},"content":{"rendered":"<h1 id=\"mysql%e5%ad%97%e7%ac%a6%e4%b8%b2%e8%99%95%e7%90%86-XnZbJzvVZs\">MySQL\u5b57\u7b26\u4e32\u8655\u7406<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u5b57\u7b26\u4e32\u8655\u7406\u662f\u4e00\u500b\u81f3\u95dc\u91cd\u8981\u7684\u529f\u80fd\uff0c\u5c24\u5176\u662f\u5728\u4f7f\u7528MySQL\u6642\u3002MySQL\u63d0\u4f9b\u4e86\u591a\u7a2e\u5167\u5efa\u51fd\u6578\u4f86\u8655\u7406\u5b57\u7b26\u4e32\uff0c\u9019\u4e9b\u51fd\u6578\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u9032\u884c\u6578\u64da\u6e05\u7406\u3001\u683c\u5f0f\u5316\u548c\u67e5\u8a62\u7b49\u64cd\u4f5c\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eMySQL\u4e2d\u7684\u5b57\u7b26\u4e32\u8655\u7406\u6280\u8853\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u3002<\/p>\n<h2 id=\"%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%87%bd%e6%95%b8%e6%a6%82%e8%bf%b0-XnZbJzvVZs\">\u5b57\u7b26\u4e32\u51fd\u6578\u6982\u8ff0<\/h2>\n<p>MySQL\u63d0\u4f9b\u4e86\u591a\u7a2e\u5b57\u7b26\u4e32\u51fd\u6578\uff0c\u9019\u4e9b\u51fd\u6578\u53ef\u4ee5\u5206\u70ba\u5e7e\u500b\u4e3b\u8981\u985e\u5225\uff1a<\/p>\n<ul>\n<li><strong>\u5b57\u7b26\u4e32\u9577\u5ea6\u51fd\u6578\uff1a<\/strong>\u5982 <code>LENGTH()<\/code> \u548c <code>CHAR_LENGTH()<\/code>\uff0c\u7528\u65bc\u8a08\u7b97\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u3002<\/li>\n<li><strong>\u5b57\u7b26\u4e32\u67e5\u8a62\u51fd\u6578\uff1a<\/strong>\u5982 <code>LOCATE()<\/code> \u548c <code>INSTR()<\/code>\uff0c\u7528\u65bc\u67e5\u627e\u5b50\u5b57\u7b26\u4e32\u7684\u4f4d\u7f6e\u3002<\/li>\n<li><strong>\u5b57\u7b26\u4e32\u4fee\u6539\u51fd\u6578\uff1a<\/strong>\u5982 <code>CONCAT()<\/code> \u548c <code>SUBSTRING()<\/code>\uff0c\u7528\u65bc\u4fee\u6539\u5b57\u7b26\u4e32\u7684\u5167\u5bb9\u3002<\/li>\n<li><strong>\u5b57\u7b26\u4e32\u683c\u5f0f\u5316\u51fd\u6578\uff1a<\/strong>\u5982 <code>UPPER()<\/code> \u548c <code>LOWER()<\/code>\uff0c\u7528\u65bc\u6539\u8b8a\u5b57\u7b26\u4e32\u7684\u5927\u5c0f\u5beb\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%b8%b8%e7%94%a8%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%87%bd%e6%95%b8%e7%a4%ba%e4%be%8b-XnZbJzvVZs\">\u5e38\u7528\u5b57\u7b26\u4e32\u51fd\u6578\u793a\u4f8b<\/h2>\n<h3 id=\"1-%e5%ad%97%e7%ac%a6%e4%b8%b2%e9%95%b7%e5%ba%a6-XnZbJzvVZs\">1. \u5b57\u7b26\u4e32\u9577\u5ea6<\/h3>\n<p>\u4f7f\u7528 <code>LENGTH()<\/code> \u51fd\u6578\u53ef\u4ee5\u7372\u53d6\u5b57\u7b26\u4e32\u7684\u5b57\u7bc0\u9577\u5ea6\uff0c\u800c <code>CHAR_LENGTH()<\/code> \u5247\u8fd4\u56de\u5b57\u7b26\u6578\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT LENGTH('Hello, World!'); -- \u8fd4\u56de 13\nSELECT CHAR_LENGTH('Hello, World!'); -- \u8fd4\u56de 13\n<\/code><\/pre>\n<h3 id=\"2-%e5%ad%97%e7%ac%a6%e4%b8%b2%e6%9f%a5%e8%a9%a2-XnZbJzvVZs\">2. \u5b57\u7b26\u4e32\u67e5\u8a62<\/h3>\n<p>\u5982\u679c\u9700\u8981\u67e5\u627e\u67d0\u500b\u5b50\u5b57\u7b26\u4e32\u5728\u4e3b\u5b57\u7b26\u4e32\u4e2d\u7684\u4f4d\u7f6e\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>LOCATE()<\/code> \u51fd\u6578\uff1a<\/p>\n<pre><code>SELECT LOCATE('World', 'Hello, World!'); -- \u8fd4\u56de 8\n<\/code><\/pre>\n<h3 id=\"3-%e5%ad%97%e7%ac%a6%e4%b8%b2%e6%8b%bc%e6%8e%a5-XnZbJzvVZs\">3. \u5b57\u7b26\u4e32\u62fc\u63a5<\/h3>\n<p>\u4f7f\u7528 <code>CONCAT()<\/code> \u51fd\u6578\u53ef\u4ee5\u5c07\u591a\u500b\u5b57\u7b26\u4e32\u9023\u63a5\u5728\u4e00\u8d77\uff1a<\/p>\n<pre><code>SELECT CONCAT('Hello', ', ', 'World!'); -- \u8fd4\u56de 'Hello, World!'\n<\/code><\/pre>\n<h3 id=\"4-%e5%ad%97%e7%ac%a6%e4%b8%b2%e6%88%aa%e5%8f%96-XnZbJzvVZs\">4. \u5b57\u7b26\u4e32\u622a\u53d6<\/h3>\n<p>\u4f7f\u7528 <code>SUBSTRING()<\/code> \u51fd\u6578\u53ef\u4ee5\u5f9e\u5b57\u7b26\u4e32\u4e2d\u63d0\u53d6\u5b50\u5b57\u7b26\u4e32\uff1a<\/p>\n<pre><code>SELECT SUBSTRING('Hello, World!', 1, 5); -- \u8fd4\u56de 'Hello'\n<\/code><\/pre>\n<h3 id=\"5-%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%a4%a7%e5%b0%8f%e5%af%ab%e8%bd%89%e6%8f%9b-XnZbJzvVZs\">5. \u5b57\u7b26\u4e32\u5927\u5c0f\u5beb\u8f49\u63db<\/h3>\n<p>\u4f7f\u7528 <code>UPPER()<\/code> \u548c <code>LOWER()<\/code> \u51fd\u6578\u53ef\u4ee5\u6539\u8b8a\u5b57\u7b26\u4e32\u7684\u5927\u5c0f\u5beb\uff1a<\/p>\n<pre><code>SELECT UPPER('Hello, World!'); -- \u8fd4\u56de 'HELLO, WORLD!'\nSELECT LOWER('Hello, World!'); -- \u8fd4\u56de 'hello, world!'\n<\/code><\/pre>\n<h2 id=\"%e5%ad%97%e7%ac%a6%e4%b8%b2%e8%99%95%e7%90%86%e7%9a%84%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-XnZbJzvVZs\">\u5b57\u7b26\u4e32\u8655\u7406\u7684\u61c9\u7528\u5834\u666f<\/h2>\n<p>\u5b57\u7b26\u4e32\u8655\u7406\u5728\u8a31\u591a\u61c9\u7528\u5834\u666f\u4e2d\u90fd\u975e\u5e38\u91cd\u8981\uff0c\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li><strong>\u6578\u64da\u6e05\u7406\uff1a<\/strong>\u5728\u5c0e\u5165\u6578\u64da\u6642\uff0c\u53ef\u80fd\u9700\u8981\u53bb\u9664\u591a\u9918\u7684\u7a7a\u683c\u6216\u7279\u6b8a\u5b57\u7b26\u3002<\/li>\n<li><strong>\u5831\u544a\u751f\u6210\uff1a<\/strong>\u5728\u751f\u6210\u5831\u544a\u6642\uff0c\u53ef\u80fd\u9700\u8981\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\u4ee5\u7b26\u5408\u7279\u5b9a\u7684\u986f\u793a\u8981\u6c42\u3002<\/li>\n<li><strong>\u7528\u6236\u8f38\u5165\u9a57\u8b49\uff1a<\/strong>\u5728\u8655\u7406\u7528\u6236\u8f38\u5165\u6642\uff0c\u53ef\u80fd\u9700\u8981\u6aa2\u67e5\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u6216\u683c\u5f0f\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-XnZbJzvVZs\">\u7e3d\u7d50<\/h2>\n<p>MySQL\u7684\u5b57\u7b26\u4e32\u8655\u7406\u529f\u80fd\u70ba\u958b\u767c\u8005\u63d0\u4f9b\u4e86\u5f37\u5927\u7684\u5de5\u5177\u4f86\u64cd\u4f5c\u548c\u7ba1\u7406\u6578\u64da\u3002\u901a\u904e\u4f7f\u7528\u5404\u7a2e\u5b57\u7b26\u4e32\u51fd\u6578\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u8f15\u9b06\u5730\u9032\u884c\u6578\u64da\u6e05\u7406\u3001\u683c\u5f0f\u5316\u548c\u67e5\u8a62\u7b49\u64cd\u4f5c\u3002\u7121\u8ad6\u662f\u5728\u6578\u64da\u5eab\u8a2d\u8a08\u9084\u662f\u61c9\u7528\u958b\u767c\u4e2d\uff0c\u638c\u63e1\u9019\u4e9b\u5b57\u7b26\u4e32\u8655\u7406\u6280\u8853\u90fd\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u6578\u64da\u5eab\u7ba1\u7406\u9084\u662f\u61c9\u7528\u90e8\u7f72\uff0c\u6211\u5011\u7684 <a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a> \u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22MySQL\u5b57\u7b26\u4e32\u8655\u7406\u6280\u5de7\uff0c\u5b78\u7fd2\u5982\u4f55\u6709\u6548\u5730\u64cd\u4f5c\u3001\u67e5\u8a62\u548c\u8f49\u63db\u5b57\u7b26\u4e32\u6578\u64da\uff0c\u63d0\u5347\u6578\u64da\u5eab\u7ba1\u7406\u6548\u7387\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-80762","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/80762","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=80762"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/80762\/revisions"}],"predecessor-version":[{"id":80763,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/80762\/revisions\/80763"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=80762"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=80762"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=80762"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}