{"id":80203,"date":"2024-10-16T14:03:14","date_gmt":"2024-10-16T06:03:14","guid":{"rendered":"https:\/\/server.hk\/cnblog\/80203\/"},"modified":"2024-10-16T14:03:14","modified_gmt":"2024-10-16T06:03:14","slug":"mysql%e6%8c%87%e4%bb%a4-varchar%ef%bc%88%e5%8f%af%e8%ae%8a%e9%95%b7%e5%ba%a6%e5%ad%97%e7%ac%a6%e4%b8%b2%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/80203\/","title":{"rendered":"MySQL\u6307\u4ee4: VARCHAR\uff08\u53ef\u8b8a\u9577\u5ea6\u5b57\u7b26\u4e32\uff09"},"content":{"rendered":"<h1 id=\"mysql%e6%8c%87%e4%bb%a4-varchar%ef%bc%88%e5%8f%af%e8%ae%8a%e9%95%b7%e5%ba%a6%e5%ad%97%e7%ac%a6%e4%b8%b2%ef%bc%89-NRIlfIEQRs\">MySQL\u6307\u4ee4: VARCHAR\uff08\u53ef\u8b8a\u9577\u5ea6\u5b57\u7b26\u4e32\uff09<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u8a2d\u8a08\u4e2d\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b\u5c0d\u65bc\u6578\u64da\u7684\u5b58\u5132\u548c\u6027\u80fd\u81f3\u95dc\u91cd\u8981\u3002MySQL\u4f5c\u70ba\u4e00\u500b\u6d41\u884c\u7684\u958b\u6e90\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u591a\u7a2e\u6578\u64da\u985e\u578b\uff0c\u5176\u4e2d\u4e4b\u4e00\u5c31\u662fVARCHAR\uff08\u53ef\u8b8a\u9577\u5ea6\u5b57\u7b26\u4e32\uff09\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eVARCHAR\u7684\u7279\u6027\u3001\u4f7f\u7528\u5834\u666f\u53ca\u5176\u5728MySQL\u4e2d\u7684\u61c9\u7528\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%afvarchar%ef%bc%9f-NRIlfIEQRs\">\u4ec0\u9ebc\u662fVARCHAR\uff1f<\/h2>\n<p>VARCHAR\u662f\u4e00\u7a2e\u53ef\u8b8a\u9577\u5ea6\u7684\u5b57\u7b26\u4e32\u6578\u64da\u985e\u578b\uff0c\u5141\u8a31\u7528\u6236\u5b58\u5132\u9577\u5ea6\u4e0d\u4e00\u7684\u5b57\u7b26\u4e32\u3002\u8207\u56fa\u5b9a\u9577\u5ea6\u7684CHAR\u985e\u578b\u76f8\u6bd4\uff0cVARCHAR\u80fd\u5920\u66f4\u6709\u6548\u5730\u5229\u7528\u5b58\u5132\u7a7a\u9593\uff0c\u56e0\u70ba\u5b83\u53ea\u4f54\u7528\u5be6\u969b\u5b58\u5132\u7684\u5b57\u7b26\u6578\u91cf\u52a0\u4e0a\u4e00\u500b\u6216\u5169\u500b\u5b57\u7bc0\u7684\u984d\u5916\u958b\u92b7\uff08\u7528\u65bc\u5b58\u5132\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\uff09\u3002<\/p>\n<h2 id=\"varchar%e7%9a%84%e7%89%b9%e6%80%a7-NRIlfIEQRs\">VARCHAR\u7684\u7279\u6027<\/h2>\n<ul>\n<li><strong>\u53ef\u8b8a\u9577\u5ea6\uff1a<\/strong>VARCHAR\u53ef\u4ee5\u5b58\u5132\u5f9e0\u523065535\u500b\u5b57\u7b26\uff0c\u5177\u9ad4\u53d6\u6c7a\u65bc\u5b57\u7b26\u96c6\u548c\u884c\u7684\u6700\u5927\u9577\u5ea6\u3002<\/li>\n<li><strong>\u5b58\u5132\u6548\u7387\uff1a<\/strong>\u7531\u65bc\u5176\u53ef\u8b8a\u9577\u5ea6\u7684\u7279\u6027\uff0cVARCHAR\u5728\u5b58\u5132\u7a7a\u9593\u4e0a\u6bd4CHAR\u66f4\u5177\u512a\u52e2\uff0c\u7279\u5225\u662f\u5728\u5b58\u5132\u9577\u5ea6\u4e0d\u4e00\u7684\u5b57\u7b26\u4e32\u6642\u3002<\/li>\n<li><strong>\u5b57\u7b26\u96c6\u652f\u6301\uff1a<\/strong>VARCHAR\u652f\u6301\u591a\u7a2e\u5b57\u7b26\u96c6\uff0c\u5305\u62ecUTF-8\uff0c\u9019\u4f7f\u5f97\u5b83\u80fd\u5920\u5b58\u5132\u591a\u8a9e\u8a00\u6587\u672c\u3002<\/li>\n<\/ul>\n<h2 id=\"varchar%e7%9a%84%e4%bd%bf%e7%94%a8%e5%a0%b4%e6%99%af-NRIlfIEQRs\">VARCHAR\u7684\u4f7f\u7528\u5834\u666f<\/h2>\n<p>VARCHAR\u9069\u5408\u7528\u65bc\u5b58\u5132\u9577\u5ea6\u4e0d\u56fa\u5b9a\u7684\u6578\u64da\uff0c\u4f8b\u5982\u7528\u6236\u540d\u3001\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u3001\u5730\u5740\u7b49\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5177\u9ad4\u7684\u4f7f\u7528\u5834\u666f\uff1a<\/p>\n<ul>\n<li><strong>\u7528\u6236\u540d\uff1a<\/strong>\u7528\u6236\u540d\u7684\u9577\u5ea6\u901a\u5e38\u4e0d\u56fa\u5b9a\uff0c\u4f7f\u7528VARCHAR\u53ef\u4ee5\u6709\u6548\u7bc0\u7701\u5b58\u5132\u7a7a\u9593\u3002<\/li>\n<li><strong>\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\uff1a<\/strong>\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u7684\u9577\u5ea6\u4e5f\u4e0d\u4e00\u81f4\uff0c\u4f7f\u7528VARCHAR\u53ef\u4ee5\u9748\u6d3b\u61c9\u5c0d\u4e0d\u540c\u9577\u5ea6\u7684\u9700\u6c42\u3002<\/li>\n<li><strong>\u63cf\u8ff0\u6027\u6587\u672c\uff1a<\/strong>\u5982\u7522\u54c1\u63cf\u8ff0\u6216\u8a55\u8ad6\uff0c\u9019\u4e9b\u6587\u672c\u7684\u9577\u5ea6\u901a\u5e38\u8b8a\u5316\u8f03\u5927\uff0c\u4f7f\u7528VARCHAR\u53ef\u4ee5\u66f4\u597d\u5730\u9069\u61c9\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e5%9c%a8mysql%e4%b8%ad%e4%bd%bf%e7%94%a8varchar-NRIlfIEQRs\">\u5982\u4f55\u5728MySQL\u4e2d\u4f7f\u7528VARCHAR<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c\u5b9a\u7fa9VARCHAR\u5b57\u6bb5\u7684\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>CREATE TABLE users (\n    id INT AUTO_INCREMENT PRIMARY KEY,\n    username VARCHAR(50),\n    email VARCHAR(100)\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u5275\u5efa\u4e86\u4e00\u500b\u540d\u70bausers\u7684\u8868\uff0c\u5176\u4e2dusername\u5b57\u6bb5\u7684\u6700\u5927\u9577\u5ea6\u70ba50\u500b\u5b57\u7b26\uff0cemail\u5b57\u6bb5\u7684\u6700\u5927\u9577\u5ea6\u70ba100\u500b\u5b57\u7b26\u3002<\/p>\n<h2 id=\"varchar%e7%9a%84%e9%99%90%e5%88%b6-NRIlfIEQRs\">VARCHAR\u7684\u9650\u5236<\/h2>\n<p>\u5118\u7ba1VARCHAR\u6709\u8a31\u591a\u512a\u9ede\uff0c\u4f46\u4e5f\u5b58\u5728\u4e00\u4e9b\u9650\u5236\uff1a<\/p>\n<ul>\n<li><strong>\u6027\u80fd\u554f\u984c\uff1a<\/strong>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528VARCHAR\u53ef\u80fd\u6703\u5c0e\u81f4\u6027\u80fd\u4e0b\u964d\uff0c\u7279\u5225\u662f\u5728\u9032\u884c\u5927\u91cf\u5b57\u7b26\u4e32\u64cd\u4f5c\u6642\u3002<\/li>\n<li><strong>\u6700\u5927\u9577\u5ea6\u9650\u5236\uff1a<\/strong>VARCHAR\u7684\u6700\u5927\u9577\u5ea6\u53d7\u9650\u65bc\u884c\u7684\u6700\u5927\u9577\u5ea6\uff0c\u9019\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\u53ef\u80fd\u6703\u6210\u70ba\u74f6\u9838\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-NRIlfIEQRs\">\u7e3d\u7d50<\/h2>\n<p>\u7e3d\u7684\u4f86\u8aaa\uff0cVARCHAR\u662f\u4e00\u7a2e\u9748\u6d3b\u4e14\u9ad8\u6548\u7684\u6578\u64da\u985e\u578b\uff0c\u9069\u5408\u7528\u65bc\u5b58\u5132\u9577\u5ea6\u4e0d\u4e00\u7684\u5b57\u7b26\u4e32\u3002\u5728\u8a2d\u8a08\u6578\u64da\u5eab\u6642\uff0c\u5408\u7406\u9078\u64c7\u6578\u64da\u985e\u578b\u80fd\u5920\u63d0\u9ad8\u5b58\u5132\u6548\u7387\u548c\u6027\u80fd\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u5b58\u5132\u7684\u7528\u6236\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u7121\u8ad6\u662f\u9078\u64c7 <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u9084\u662f\u5176\u4ed6\u985e\u578b\u7684 <a href=\"https:\/\/server.hk\">\u96f2\u4f3a\u670d\u5668<\/a>\uff0c\u90fd\u80fd\u70ba\u60a8\u7684\u6578\u64da\u5eab\u61c9\u7528\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u4e2d\u7684VARCHAR\u6307\u4ee4\uff0c\u638c\u63e1\u53ef\u53d8\u957f\u5ea6\u5b57\u7b26\u4e32\u7684\u4f7f\u7528\u65b9\u6cd5\u53ca\u5176\u5728\u6570\u636e\u5e93\u8bbe\u8ba1\u4e2d\u7684\u91cd\u8981\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-80203","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/80203","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=80203"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/80203\/revisions"}],"predecessor-version":[{"id":80204,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/80203\/revisions\/80204"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=80203"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=80203"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=80203"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}