{"id":79116,"date":"2024-10-16T12:40:16","date_gmt":"2024-10-16T04:40:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/79116\/"},"modified":"2024-10-16T12:40:16","modified_gmt":"2024-10-16T04:40:16","slug":"mysql%e6%8c%87%e4%bb%a4-lpad%ef%bc%88%e5%b7%a6%e5%81%b4%e5%a1%ab%e5%85%85%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/79116\/","title":{"rendered":"MySQL\u6307\u4ee4: LPAD()\uff08\u5de6\u5074\u586b\u5145\uff09"},"content":{"rendered":"<h1 id=\"mysql%e6%8c%87%e4%bb%a4-lpad%ef%bc%88%e5%b7%a6%e5%81%b4%e5%a1%ab%e5%85%85%ef%bc%89-imufsdOiqC\">MySQL\u6307\u4ee4: LPAD()\uff08\u5de6\u5074\u586b\u5145\uff09<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u4e2d\uff0cMySQL\u662f\u4e00\u500b\u5ee3\u6cdb\u4f7f\u7528\u7684\u95dc\u806f\u5f0f\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u3002\u5b83\u63d0\u4f9b\u4e86\u591a\u7a2e\u529f\u80fd\u5f37\u5927\u7684\u6307\u4ee4\u4f86\u8655\u7406\u548c\u64cd\u4f5c\u6578\u64da\u3002\u5176\u4e2d\uff0cLPAD()\u51fd\u6578\u662f\u4e00\u500b\u975e\u5e38\u5be6\u7528\u7684\u5de5\u5177\uff0c\u7279\u5225\u662f\u5728\u9700\u8981\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\u6642\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eLPAD()\u51fd\u6578\u7684\u7528\u6cd5\u53ca\u5176\u61c9\u7528\u5834\u666f\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%aflpad%e5%87%bd%e6%95%b8%ef%bc%9f-imufsdOiqC\">\u4ec0\u9ebc\u662fLPAD()\u51fd\u6578\uff1f<\/h2>\n<p>LPAD()\u51fd\u6578\u7684\u5168\u540d\u662f\u201cLeft Padding\u201d\uff0c\u5176\u4e3b\u8981\u529f\u80fd\u662f\u5c07\u6307\u5b9a\u7684\u5b57\u7b26\u4e32\u586b\u5145\u5230\u5de6\u5074\uff0c\u76f4\u5230\u9054\u5230\u6307\u5b9a\u7684\u7e3d\u9577\u5ea6\u3002\u9019\u5728\u9700\u8981\u7d71\u4e00\u6578\u64da\u683c\u5f0f\u6642\u7279\u5225\u6709\u7528\uff0c\u4f8b\u5982\u5728\u5831\u8868\u4e2d\u986f\u793a\u7de8\u865f\u6216\u4ee3\u78bc\u6642\u3002<\/p>\n<h2 id=\"lpad%e5%87%bd%e6%95%b8%e7%9a%84%e8%aa%9e%e6%b3%95-imufsdOiqC\">LPAD()\u51fd\u6578\u7684\u8a9e\u6cd5<\/h2>\n<pre><code>LPAD(string, length, pad_string)<\/code><\/pre>\n<ul>\n<li><strong>string<\/strong>: \u9700\u8981\u586b\u5145\u7684\u539f\u59cb\u5b57\u7b26\u4e32\u3002<\/li>\n<li><strong>length<\/strong>: \u6700\u7d42\u5b57\u7b26\u4e32\u7684\u7e3d\u9577\u5ea6\u3002\u5982\u679c\u539f\u59cb\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u5927\u65bc\u6b64\u503c\uff0c\u5247\u8fd4\u56de\u539f\u59cb\u5b57\u7b26\u4e32\u3002<\/li>\n<li><strong>pad_string<\/strong>: \u7528\u65bc\u586b\u5145\u7684\u5b57\u7b26\u4e32\u3002\u5982\u679c\u6b64\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u5927\u65bc\u5269\u9918\u7684\u586b\u5145\u7a7a\u9593\uff0c\u5247\u53ea\u53d6\u5176\u5de6\u5074\u90e8\u5206\u3002<\/li>\n<\/ul>\n<h2 id=\"lpad%e5%87%bd%e6%95%b8%e7%9a%84%e7%a4%ba%e4%be%8b-imufsdOiqC\">LPAD()\u51fd\u6578\u7684\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u4e9b\u4f7f\u7528LPAD()\u51fd\u6578\u7684\u793a\u4f8b\uff0c\u5e6b\u52a9\u60a8\u66f4\u597d\u5730\u7406\u89e3\u5176\u7528\u6cd5\uff1a<\/p>\n<h3 id=\"%e7%a4%ba%e4%be%8b1-%e5%9f%ba%e6%9c%ac%e7%94%a8%e6%b3%95-imufsdOiqC\">\u793a\u4f8b1: \u57fa\u672c\u7528\u6cd5<\/h3>\n<pre><code>SELECT LPAD('123', 5, '0');<\/code><\/pre>\n<p>\u9019\u689d\u6307\u4ee4\u5c07\u8fd4\u56de\u201c00123\u201d\u3002\u539f\u59cb\u5b57\u7b26\u4e32\u201c123\u201d\u88ab\u586b\u5145\u4e86\u5169\u500b\u201c0\u201d\u4ee5\u9054\u5230\u7e3d\u9577\u5ea65\u3002<\/p>\n<h3 id=\"%e7%a4%ba%e4%be%8b2-%e4%bd%bf%e7%94%a8%e4%b8%8d%e5%90%8c%e7%9a%84%e5%a1%ab%e5%85%85%e5%ad%97%e7%ac%a6-imufsdOiqC\">\u793a\u4f8b2: \u4f7f\u7528\u4e0d\u540c\u7684\u586b\u5145\u5b57\u7b26<\/h3>\n<pre><code>SELECT LPAD('A', 4, '*');<\/code><\/pre>\n<p>\u9019\u689d\u6307\u4ee4\u5c07\u8fd4\u56de\u201c***A\u201d\u3002\u5728\u9019\u88e1\uff0c\u5b57\u7b26\u201c*\u201d\u88ab\u7528\u4f86\u586b\u5145\u5de6\u5074\uff0c\u76f4\u5230\u9054\u5230\u7e3d\u9577\u5ea64\u3002<\/p>\n<h3 id=\"%e7%a4%ba%e4%be%8b3-%e7%95%b6%e5%8e%9f%e5%a7%8b%e5%ad%97%e7%ac%a6%e4%b8%b2%e9%95%b7%e5%ba%a6%e8%b6%85%e9%81%8e%e6%8c%87%e5%ae%9a%e9%95%b7%e5%ba%a6-imufsdOiqC\">\u793a\u4f8b3: \u7576\u539f\u59cb\u5b57\u7b26\u4e32\u9577\u5ea6\u8d85\u904e\u6307\u5b9a\u9577\u5ea6<\/h3>\n<pre><code>SELECT LPAD('HelloWorld', 5, 'X');<\/code><\/pre>\n<p>\u9019\u689d\u6307\u4ee4\u5c07\u8fd4\u56de\u201cHelloWorld\u201d\u3002\u56e0\u70ba\u539f\u59cb\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u5df2\u7d93\u8d85\u904e5\uff0c\u6240\u4ee5\u8fd4\u56de\u539f\u59cb\u5b57\u7b26\u4e32\u672c\u8eab\u3002<\/p>\n<h2 id=\"lpad%e5%87%bd%e6%95%b8%e7%9a%84%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-imufsdOiqC\">LPAD()\u51fd\u6578\u7684\u61c9\u7528\u5834\u666f<\/h2>\n<p>LPAD()\u51fd\u6578\u5728\u591a\u7a2e\u60c5\u6cc1\u4e0b\u90fd\u975e\u5e38\u6709\u7528\uff0c\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u61c9\u7528\u5834\u666f\uff1a<\/p>\n<ul>\n<li><strong>\u5831\u8868\u751f\u6210<\/strong>: \u5728\u751f\u6210\u5831\u8868\u6642\uff0c\u53ef\u80fd\u9700\u8981\u5c07\u7de8\u865f\u683c\u5f0f\u5316\u70ba\u56fa\u5b9a\u9577\u5ea6\uff0c\u4ee5\u4fbf\u65bc\u95b1\u8b80\u548c\u6bd4\u8f03\u3002<\/li>\n<li><strong>\u6578\u64da\u6e05\u7406<\/strong>: \u5728\u6578\u64da\u6e05\u7406\u904e\u7a0b\u4e2d\uff0c\u53ef\u80fd\u9700\u8981\u7d71\u4e00\u5b57\u7b26\u4e32\u7684\u683c\u5f0f\uff0c\u4ee5\u4fbf\u65bc\u5f8c\u7e8c\u7684\u6578\u64da\u5206\u6790\u3002<\/li>\n<li><strong>\u7528\u6236\u754c\u9762\u986f\u793a<\/strong>: \u5728\u7528\u6236\u754c\u9762\u4e2d\u986f\u793a\u6578\u64da\u6642\uff0c\u7d71\u4e00\u683c\u5f0f\u53ef\u4ee5\u63d0\u9ad8\u7528\u6236\u9ad4\u9a57\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-imufsdOiqC\">\u7e3d\u7d50<\/h2>\n<p>LPAD()\u51fd\u6578\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u5728MySQL\u4e2d\u9032\u884c\u5b57\u7b26\u4e32\u7684\u5de6\u5074\u586b\u5145\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528\u6b64\u51fd\u6578\uff0c\u53ef\u4ee5\u63d0\u9ad8\u6578\u64da\u7684\u53ef\u8b80\u6027\u548c\u4e00\u81f4\u6027\u3002\u7121\u8ad6\u662f\u5728\u5831\u8868\u751f\u6210\u3001\u6578\u64da\u6e05\u7406\u9084\u662f\u7528\u6236\u754c\u9762\u986f\u793a\u4e2d\uff0cLPAD()\u90fd\u80fd\u767c\u63ee\u91cd\u8981\u4f5c\u7528\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u652f\u6301\u60a8\u7684\u6578\u64da\u5eab\u9700\u6c42\uff0cServer.HK \u63d0\u4f9b\u4e86\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u7528\u6236\u7684\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u6307\u4ee4LPAD()\uff0c\u7528\u65bc\u5728\u5b57\u4e32\u5de6\u5074\u586b\u5145\u6307\u5b9a\u5b57\u7b26\uff0c\u4fbf\u65bc\u683c\u5f0f\u5316\u6578\u64da\u548c\u63d0\u5347\u53ef\u8b80\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-79116","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/79116","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=79116"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/79116\/revisions"}],"predecessor-version":[{"id":79117,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/79116\/revisions\/79117"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=79116"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=79116"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=79116"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}