{"id":75876,"date":"2024-10-16T01:58:16","date_gmt":"2024-10-15T17:58:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/75876\/"},"modified":"2024-10-16T01:58:16","modified_gmt":"2024-10-15T17:58:16","slug":"mysql-%e5%ad%98%e5%84%b2%e7%a7%98%e5%af%86%e6%8f%ad%e7%a4%ba%ef%bc%9achar-vs-varchar%ef%bc%8c%e8%a7%a3%e9%8e%96%e5%ae%9a%e9%95%b7%e7%a5%9e%e5%99%a8%e7%9a%84%e7%b5%82%e6%a5%b5%e9%81%b8%e6%93%87","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/75876\/","title":{"rendered":"MySQL \u5b58\u5132\u79d8\u5bc6\u63ed\u793a\uff1aCHAR vs.VARCHAR\uff0c\u89e3\u9396\u5b9a\u9577\u795e\u5668\u7684\u7d42\u6975\u9078\u64c7\u6307\u5357\uff01"},"content":{"rendered":"<h1 id=\"mysql-%e5%ad%98%e5%84%b2%e7%a7%98%e5%af%86%e6%8f%ad%e7%a4%ba%ef%bc%9achar-vs-varchar%ef%bc%8c%e8%a7%a3%e9%8e%96%e5%ae%9a%e9%95%b7%e7%a5%9e%e5%99%a8%e7%9a%84%e7%b5%82%e6%a5%b5%e9%81%b8%e6%93%87-aXEvuvwNEF\">MySQL \u5b58\u5132\u79d8\u5bc6\u63ed\u793a\uff1aCHAR vs. VARCHAR\uff0c\u89e3\u9396\u5b9a\u9577\u795e\u5668\u7684\u7d42\u6975\u9078\u64c7\u6307\u5357\uff01<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u8a2d\u8a08\u4e2d\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b\u5c0d\u65bc\u6027\u80fd\u548c\u5b58\u5132\u6548\u7387\u81f3\u95dc\u91cd\u8981\u3002MySQL \u63d0\u4f9b\u4e86\u591a\u7a2e\u5b57\u7b26\u6578\u64da\u985e\u578b\uff0c\u5176\u4e2d\u6700\u5e38\u7528\u7684\u5169\u7a2e\u662f <code>CHAR<\/code> \u548c <code>VARCHAR<\/code>\u3002\u9019\u7bc7\u6587\u7ae0\u5c07\u6df1\u5165\u63a2\u8a0e\u9019\u5169\u8005\u7684\u7279\u9ede\u3001\u512a\u7f3a\u9ede\u4ee5\u53ca\u9069\u7528\u5834\u666f\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u505a\u51fa\u660e\u667a\u7684\u9078\u64c7\u3002<\/p>\n<h2 id=\"char-%e8%88%87-varchar-%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-aXEvuvwNEF\">CHAR \u8207 VARCHAR \u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p><code>CHAR<\/code> \u662f\u4e00\u7a2e\u5b9a\u9577\u5b57\u7b26\u4e32\u6578\u64da\u985e\u578b\uff0c\u7121\u8ad6\u5be6\u969b\u5b58\u5132\u7684\u5b57\u7b26\u6578\u91cf\u662f\u591a\u5c11\uff0cMySQL \u90fd\u6703\u70ba\u5176\u5206\u914d\u56fa\u5b9a\u7684\u7a7a\u9593\u3002\u4f8b\u5982\uff0c\u5b9a\u7fa9\u4e00\u500b <code>CHAR(10)<\/code> \u7684\u5b57\u6bb5\uff0c\u7121\u8ad6\u5be6\u969b\u5b58\u5132\u7684\u5b57\u7b26\u6578\u91cf\u662f 5 \u9084\u662f 10\uff0cMySQL \u90fd\u6703\u4f54\u7528 10 \u500b\u5b57\u7b26\u7684\u7a7a\u9593\u3002<\/p>\n<p>\u76f8\u5c0d\u800c\u8a00\uff0c<code>VARCHAR<\/code> \u662f\u4e00\u7a2e\u8b8a\u9577\u5b57\u7b26\u4e32\u6578\u64da\u985e\u578b\uff0c\u6839\u64da\u5be6\u969b\u5b58\u5132\u7684\u5b57\u7b26\u6578\u91cf\u4f86\u5206\u914d\u7a7a\u9593\u3002\u5b9a\u7fa9\u4e00\u500b <code>VARCHAR(10)<\/code> \u7684\u5b57\u6bb5\uff0c\u82e5\u5be6\u969b\u5b58\u5132 5 \u500b\u5b57\u7b26\uff0c\u5247\u53ea\u4f54\u7528 5 \u500b\u5b57\u7b26\u7684\u7a7a\u9593\uff0c\u52a0\u4e0a 1 \u6216 2 \u500b\u5b57\u7bc0\u7684\u984d\u5916\u958b\u92b7\u4f86\u5b58\u5132\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u3002<\/p>\n<h2 id=\"char-%e7%9a%84%e5%84%aa%e7%bc%ba%e9%bb%9e-aXEvuvwNEF\">CHAR \u7684\u512a\u7f3a\u9ede<\/h2>\n<h3 id=\"%e5%84%aa%e9%bb%9e-aXEvuvwNEF\">\u512a\u9ede<\/h3>\n<ul>\n<li><strong>\u6027\u80fd\u512a\u52e2\uff1a<\/strong>\u7531\u65bc <code>CHAR<\/code> \u662f\u5b9a\u9577\u7684\uff0cMySQL \u5728\u8655\u7406\u6642\u53ef\u4ee5\u66f4\u5feb\u5730\u5b9a\u4f4d\u6578\u64da\uff0c\u7279\u5225\u662f\u5728\u9700\u8981\u983b\u7e41\u67e5\u8a62\u7684\u60c5\u6cc1\u4e0b\u3002<\/li>\n<li><strong>\u7c21\u55ae\u6027\uff1a<\/strong>\u5c0d\u65bc\u56fa\u5b9a\u9577\u5ea6\u7684\u6578\u64da\uff08\u5982\u570b\u5bb6\u4ee3\u78bc\u3001\u6027\u5225\u7b49\uff09\uff0c\u4f7f\u7528 <code>CHAR<\/code> \u53ef\u4ee5\u7c21\u5316\u6578\u64da\u5eab\u8a2d\u8a08\u3002<\/li>\n<\/ul>\n<h3 id=\"%e7%bc%ba%e9%bb%9e-aXEvuvwNEF\">\u7f3a\u9ede<\/h3>\n<ul>\n<li><strong>\u7a7a\u9593\u6d6a\u8cbb\uff1a<\/strong>\u5982\u679c\u5b58\u5132\u7684\u6578\u64da\u9577\u5ea6\u5c0f\u65bc\u5b9a\u7fa9\u7684\u9577\u5ea6\uff0c\u5247\u6703\u9020\u6210\u7a7a\u9593\u6d6a\u8cbb\u3002<\/li>\n<li><strong>\u4e0d\u9748\u6d3b\uff1a<\/strong>\u5c0d\u65bc\u8b8a\u9577\u7684\u6578\u64da\uff0c\u4f7f\u7528 <code>CHAR<\/code> \u53ef\u80fd\u6703\u5c0e\u81f4\u4e0d\u5fc5\u8981\u7684\u6027\u80fd\u640d\u5931\u3002<\/li>\n<\/ul>\n<h2 id=\"varchar-%e7%9a%84%e5%84%aa%e7%bc%ba%e9%bb%9e-aXEvuvwNEF\">VARCHAR \u7684\u512a\u7f3a\u9ede<\/h2>\n<h3 id=\"%e5%84%aa%e9%bb%9e-aXEvuvwNEF\">\u512a\u9ede<\/h3>\n<ul>\n<li><strong>\u7a7a\u9593\u6548\u7387\uff1a<\/strong><code>VARCHAR<\/code> \u6839\u64da\u5be6\u969b\u5b58\u5132\u7684\u5b57\u7b26\u6578\u91cf\u5206\u914d\u7a7a\u9593\uff0c\u80fd\u6709\u6548\u6e1b\u5c11\u5b58\u5132\u7a7a\u9593\u7684\u6d6a\u8cbb\u3002<\/li>\n<li><strong>\u9748\u6d3b\u6027\uff1a<\/strong>\u9069\u5408\u5b58\u5132\u8b8a\u9577\u7684\u6578\u64da\uff0c\u5982\u7528\u6236\u540d\u3001\u96fb\u5b50\u90f5\u4ef6\u7b49\u3002<\/li>\n<\/ul>\n<h3 id=\"%e7%bc%ba%e9%bb%9e-aXEvuvwNEF\">\u7f3a\u9ede<\/h3>\n<ul>\n<li><strong>\u6027\u80fd\u958b\u92b7\uff1a<\/strong>\u7531\u65bc <code>VARCHAR<\/code> \u662f\u8b8a\u9577\u7684\uff0cMySQL \u5728\u8655\u7406\u6642\u9700\u8981\u984d\u5916\u7684\u8a08\u7b97\u4f86\u78ba\u5b9a\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\uff0c\u9019\u53ef\u80fd\u6703\u5f71\u97ff\u6027\u80fd\u3002<\/li>\n<li><strong>\u8907\u96dc\u6027\uff1a<\/strong>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528 <code>VARCHAR<\/code> \u53ef\u80fd\u6703\u4f7f\u6578\u64da\u5eab\u8a2d\u8a08\u8b8a\u5f97\u66f4\u52a0\u8907\u96dc\u3002<\/li>\n<\/ul>\n<h2 id=\"%e9%81%b8%e6%93%87%e6%8c%87%e5%8d%97-aXEvuvwNEF\">\u9078\u64c7\u6307\u5357<\/h2>\n<p>\u5728\u9078\u64c7 <code>CHAR<\/code> \u6216 <code>VARCHAR<\/code> \u6642\uff0c\u958b\u767c\u8005\u61c9\u8003\u616e\u4ee5\u4e0b\u5e7e\u500b\u56e0\u7d20\uff1a<\/p>\n<ul>\n<li><strong>\u6578\u64da\u7279\u6027\uff1a<\/strong>\u5982\u679c\u6578\u64da\u9577\u5ea6\u56fa\u5b9a\uff0c\u5247\u9078\u64c7 <code>CHAR<\/code>\uff1b\u5982\u679c\u6578\u64da\u9577\u5ea6\u4e0d\u56fa\u5b9a\uff0c\u5247\u9078\u64c7 <code>VARCHAR<\/code>\u3002<\/li>\n<li><strong>\u6027\u80fd\u9700\u6c42\uff1a<\/strong>\u5c0d\u65bc\u9ad8\u983b\u67e5\u8a62\u7684\u5b57\u6bb5\uff0c<code>CHAR<\/code> \u53ef\u80fd\u6703\u63d0\u4f9b\u66f4\u597d\u7684\u6027\u80fd\u3002<\/li>\n<li><strong>\u5b58\u5132\u7a7a\u9593\uff1a<\/strong>\u5982\u679c\u5b58\u5132\u7a7a\u9593\u6709\u9650\uff0c\u5247\u61c9\u512a\u5148\u8003\u616e <code>VARCHAR<\/code>\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-aXEvuvwNEF\">\u7d50\u8ad6<\/h2>\n<p>\u5728 MySQL \u4e2d\uff0c<code>CHAR<\/code> \u548c <code>VARCHAR<\/code> \u5404\u6709\u5176\u512a\u7f3a\u9ede\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b\u5c0d\u65bc\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u5b58\u5132\u6548\u7387\u81f3\u95dc\u91cd\u8981\u3002\u958b\u767c\u8005\u61c9\u6839\u64da\u5177\u9ad4\u7684\u61c9\u7528\u5834\u666f\u548c\u9700\u6c42\u4f86\u505a\u51fa\u9078\u64c7\u3002\u7121\u8ad6\u662f\u9078\u64c7 <code>CHAR<\/code> \u9084\u662f <code>VARCHAR<\/code>\uff0c\u90fd\u61c9\u8a72\u5145\u5206\u8003\u616e\u6578\u64da\u7684\u7279\u6027\u548c\u6027\u80fd\u9700\u6c42\uff0c\u4ee5\u9054\u5230\u6700\u4f73\u7684\u6578\u64da\u5eab\u8a2d\u8a08\u6548\u679c\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u95dc\u65bc <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u548c\u6578\u64da\u5eab\u7ba1\u7406\u7684\u8cc7\u8a0a\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22 MySQL \u4e2d CHAR \u8207 VARCHAR \u7684\u95dc\u9375\u5dee\u7570\uff0c\u63ed\u793a\u6700\u4f73\u5b58\u5132\u9078\u64c7\uff0c\u52a9\u4f60\u512a\u5316\u6578\u64da\u5eab\u6027\u80fd\u8207\u6548\u7387\uff01<\/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-75876","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75876","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=75876"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75876\/revisions"}],"predecessor-version":[{"id":75877,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75876\/revisions\/75877"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=75876"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=75876"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=75876"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}