{"id":66624,"date":"2023-12-19T20:43:47","date_gmt":"2023-12-19T12:43:47","guid":{"rendered":"https:\/\/docs.pingcode.com\/?p=66624"},"modified":"2023-12-19T20:44:03","modified_gmt":"2023-12-19T12:44:03","slug":"char%e5%92%8cvarchar%e5%8c%ba%e5%88%ab","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/66624.html","title":{"rendered":"char\u548cvarchar\u533a\u522b"},"content":{"rendered":"\n<blockquote class=\"wp-block-quote\">\n<p>char\u548cvarchar\u662f\u5728\u6570\u636e\u5e93\u4e2d\u5e38\u7528\u7684\u4e24\u79cd\u6570\u636e\u7c7b\u578b\uff0c\u5b83\u4eec\u4e4b\u95f4\u5b58\u5728\u4e00\u4e9b\u91cd\u8981\u7684\u533a\u522b\u3002\u672c\u6587\u5c06\u6df1\u5165\u63a2\u8ba8char\u548cvarchar\u7684\u4e0d\u540c\u4e4b\u5904\uff0c\u5305\u62ec\u5b58\u50a8\u65b9\u5f0f\u3001\u7a7a\u95f4\u5229\u7528\u3001\u6027\u80fd\u4ee5\u53ca\u9002\u7528\u573a\u666f\u7b49\u65b9\u9762\u3002char\uff08Character\uff09\u662f\u4e00\u79cd\u56fa\u5b9a\u957f\u5ea6\u7684\u5b57\u7b26\u6570\u636e\u7c7b\u578b\u3002varchar\uff08Variable Character\uff09\u662f\u4e00\u79cd\u53ef\u53d8\u957f\u5ea6\u7684\u5b57\u7b26\u6570\u636e\u7c7b\u578b\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>1.<\/strong><strong>\u5b58\u50a8\u65b9\u5f0f<\/strong><\/h2>\n\n\n\n<p>char\uff08Character\uff09\u662f\u4e00\u79cd\u56fa\u5b9a\u957f\u5ea6\u7684\u5b57\u7b26\u6570\u636e\u7c7b\u578b\uff0c\u5b83\u8981\u6c42\u5728\u521b\u5efa\u8868\u65f6\u6307\u5b9a\u56fa\u5b9a\u7684\u5b57\u7b26\u957f\u5ea6\uff0c\u65e0\u8bba\u5b9e\u9645\u5b58\u50a8\u7684\u6570\u636e\u662f\u5426\u5360\u6ee1\u4e86\u6307\u5b9a\u957f\u5ea6\uff0c\u90fd\u4f1a\u5360\u7528\u6307\u5b9a\u957f\u5ea6\u7684\u5b58\u50a8\u7a7a\u95f4\u3002\u4f8b\u5982\uff0c\u5982\u679c\u521b\u5efa\u4e00\u4e2achar(10)\u5217\uff0c\u90a3\u4e48\u4e0d\u8bba\u5b9e\u9645\u5b58\u50a8\u7684\u6570\u636e\u662f5\u4e2a\u5b57\u7b26\u8fd8\u662f10\u4e2a\u5b57\u7b26\uff0c\u90fd\u4f1a\u5360\u752810\u4e2a\u5b57\u7b26\u7684\u5b58\u50a8\u7a7a\u95f4\u3002<\/p>\n\n\n\n<p>varchar\uff08Variable Character\uff09\u662f\u4e00\u79cd\u53ef\u53d8\u957f\u5ea6\u7684\u5b57\u7b26\u6570\u636e\u7c7b\u578b\uff0c\u5b83\u53ea\u4f1a\u5360\u7528\u5b9e\u9645\u5b58\u50a8\u6570\u636e\u6240\u9700\u7684\u5b58\u50a8\u7a7a\u95f4\uff0c\u4e0d\u4f1a\u6d6a\u8d39\u989d\u5916\u7684\u7a7a\u95f4\u3002\u4f8b\u5982\uff0c\u5982\u679c\u521b\u5efa\u4e00\u4e2avarchar(10)\u5217\uff0c\u5e76\u5b58\u50a8\u4e865\u4e2a\u5b57\u7b26\u7684\u6570\u636e\uff0c\u90a3\u4e48\u53ea\u4f1a\u5360\u75285\u4e2a\u5b57\u7b26\u7684\u5b58\u50a8\u7a7a\u95f4\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>2.<\/strong><strong>\u7a7a\u95f4\u5229\u7528<\/strong><\/h2>\n\n\n\n<p>\u7531\u4e8echar\u662f\u56fa\u5b9a\u957f\u5ea6\u7684\uff0c\u56e0\u6b64\u5b83\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\u4f1a\u6d6a\u8d39\u5b58\u50a8\u7a7a\u95f4\u3002\u5982\u679c\u5b58\u50a8\u7684\u6570\u636e\u8f83\u77ed\uff0cchar\u5217\u4ecd\u7136\u4f1a\u5360\u7528\u6307\u5b9a\u957f\u5ea6\u7684\u5b58\u50a8\u7a7a\u95f4\uff0c\u8fd9\u53ef\u80fd\u5bfc\u81f4\u5b58\u50a8\u6d6a\u8d39\u3002\u800cvarchar\u53ea\u5360\u7528\u5b9e\u9645\u6570\u636e\u6240\u9700\u7684\u7a7a\u95f4\uff0c\u56e0\u6b64\u66f4\u52a0\u8282\u7701\u5b58\u50a8\u8d44\u6e90\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>3.<\/strong><strong>\u6027\u80fd<\/strong><\/h2>\n\n\n\n<p>char\u5728\u67d0\u4e9b\u67e5\u8be2\u548c\u6392\u5e8f\u64cd\u4f5c\u4e0a\u53ef\u80fd\u6bd4varchar\u66f4\u5feb\uff0c\u56e0\u4e3a\u5b83\u7684\u6570\u636e\u957f\u5ea6\u662f\u56fa\u5b9a\u7684\uff0c\u6570\u636e\u5e93\u5f15\u64ce\u53ef\u4ee5\u66f4\u5bb9\u6613\u5730\u8fdb\u884c\u4f18\u5316\u3002\u4f46\u5728\u5927\u91cf\u53d8\u957f\u6570\u636e\u5b58\u50a8\u7684\u60c5\u51b5\u4e0b\uff0cvarchar\u901a\u5e38\u66f4\u5177\u6027\u80fd\u4f18\u52bf\uff0c\u56e0\u4e3a\u5b83\u53ef\u4ee5\u51cf\u5c11\u5b58\u50a8\u548c\u78c1\u76d8I\/O\u7684\u5f00\u9500\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>4.<\/strong><strong>\u9002\u7528\u573a\u666f<\/strong><\/h2>\n\n\n\n<p>\u9009\u62e9char\u8fd8\u662fvarchar\u5e94\u8be5\u6839\u636e\u5177\u4f53\u7684\u5e94\u7528\u573a\u666f\u6765\u51b3\u5b9a\u3002\u4e00\u822c\u6765\u8bf4\uff0c\u5982\u679c\u9700\u8981\u5b58\u50a8\u7684\u6570\u636e\u957f\u5ea6\u90fd\u662f\u56fa\u5b9a\u7684\uff0c\u4e14\u4e0d\u592a\u4f1a\u53d1\u751f\u53d8\u5316\uff0c\u90a3\u4e48char\u53ef\u80fd\u662f\u4e00\u4e2a\u4e0d\u9519\u7684\u9009\u62e9\u3002\u4f46\u5982\u679c\u6570\u636e\u957f\u5ea6\u53d8\u5316\u8f83\u5927\uff0c\u6216\u8005\u9700\u8981\u8282\u7701\u5b58\u50a8\u7a7a\u95f4\uff0c\u90a3\u4e48varchar\u66f4\u9002\u5408\u3002\u4f8b\u5982\uff0c\u5728\u5b58\u50a8\u7528\u6237\u8bc4\u8bba\u6216\u6587\u7ae0\u5185\u5bb9\u65f6\uff0cvarchar\u901a\u5e38\u66f4\u5177\u4f18\u52bf\uff0c\u56e0\u4e3a\u8bc4\u8bba\u548c\u6587\u7ae0\u7684\u957f\u5ea6\u53ef\u80fd\u4e0d\u540c\u3002<\/p>\n\n\n\n<p><img fetchpriority=\"high\" decoding=\"async\" width=\"484\" height=\"300\" src=\"https:\/\/cdn-docs.pingcode.com\/wp-content\/uploads\/2023\/12\/915685-char\u548cvarchar\u533a\u522b.png?x-oss-process=image\/auto-orient,1\/format,webp\" class=\"aligncenter\" alt=\"char\u548cvarchar\u533a\u522b\" \/><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>\u5e38\u89c1\u95ee\u7b54<\/strong><\/h2>\n\n\n\n<p><strong>1.char<\/strong><strong>\u548cvarchar\u6709\u4ec0\u4e48\u533a\u522b\uff1f<\/strong><\/p>\n\n\n\n<p>char\u548cvarchar\u90fd\u662f\u6570\u636e\u5e93\u4e2d\u7684\u5b57\u7b26\u6570\u636e\u7c7b\u578b\uff0c\u4e3b\u8981\u533a\u522b\u5728\u4e8e\u5b58\u50a8\u65b9\u5f0f\u3002char\u662f\u56fa\u5b9a\u957f\u5ea6\u7684\uff0c\u4f1a\u5360\u7528\u6307\u5b9a\u957f\u5ea6\u7684\u5b58\u50a8\u7a7a\u95f4\uff0c\u800cvarchar\u662f\u53ef\u53d8\u957f\u5ea6\u7684\uff0c\u53ea\u5360\u7528\u5b9e\u9645\u6570\u636e\u6240\u9700\u7684\u7a7a\u95f4\u3002<\/p>\n\n\n\n<p><strong>2.<\/strong><strong>\u5728\u4ec0\u4e48\u60c5\u51b5\u4e0b\u5e94\u8be5\u4f7f\u7528char\uff1f<\/strong><\/p>\n\n\n\n<p>char\u9002\u5408\u7528\u4e8e\u5b58\u50a8\u6570\u636e\u957f\u5ea6\u56fa\u5b9a\u3001\u4e0d\u592a\u4f1a\u53d1\u751f\u53d8\u5316\u7684\u60c5\u51b5\u3002\u4f8b\u5982\uff0c\u5b58\u50a8\u7535\u8bdd\u53f7\u7801\u6216\u90ae\u653f\u7f16\u7801\u7b49\u56fa\u5b9a\u957f\u5ea6\u7684\u6570\u636e\u65f6\uff0c\u53ef\u4ee5\u8003\u8651\u4f7f\u7528char\u3002<\/p>\n\n\n\n<p><strong>3.<\/strong><strong>\u5728\u4ec0\u4e48\u60c5\u51b5\u4e0b\u5e94\u8be5\u4f7f\u7528varchar\uff1f<\/strong><\/p>\n\n\n\n<p>varchar\u9002\u5408\u7528\u4e8e\u5b58\u50a8\u6570\u636e\u957f\u5ea6\u53d8\u5316\u8f83\u5927\u3001\u9700\u8981\u8282\u7701\u5b58\u50a8\u7a7a\u95f4\u7684\u60c5\u51b5\u3002\u4f8b\u5982\uff0c\u5b58\u50a8\u7528\u6237\u8bc4\u8bba\u6216\u6587\u7ae0\u5185\u5bb9\u65f6\uff0c\u7531\u4e8e\u957f\u5ea6\u4e0d\u56fa\u5b9a\uff0c\u901a\u5e38\u9009\u62e9\u4f7f\u7528varchar\u3002<\/p>\n\n\n\n<p><strong>4.char<\/strong><strong>\u548cvarchar\u7684\u6027\u80fd\u6709\u4f55\u533a\u522b\uff1f<\/strong><\/p>\n\n\n\n<p>char\u5728\u67d0\u4e9b\u67e5\u8be2\u548c\u6392\u5e8f\u64cd\u4f5c\u4e0a\u53ef\u80fd\u66f4\u5feb\uff0c\u56e0\u4e3a\u6570\u636e\u957f\u5ea6\u662f\u56fa\u5b9a\u7684\uff0c\u6570\u636e\u5e93\u5f15\u64ce\u53ef\u4ee5\u66f4\u5bb9\u6613\u5730\u8fdb\u884c\u4f18\u5316\u3002\u7136\u800c\uff0c\u5728\u5b58\u50a8\u5927\u91cf\u53d8\u957f\u6570\u636e\u65f6\uff0cvarchar\u901a\u5e38\u66f4\u5177\u6027\u80fd\u4f18\u52bf\uff0c\u56e0\u4e3a\u5b83\u53ef\u4ee5\u51cf\u5c11\u5b58\u50a8\u548c\u78c1\u76d8I\/O\u7684\u5f00\u9500\u3002<\/p>\n\n\n\n<p><strong>5.<\/strong><strong>\u662f\u5426\u53ef\u4ee5\u5728\u8868\u7684\u8bbe\u8ba1\u4e2d\u6df7\u5408\u4f7f\u7528char\u548cvarchar\uff1f<\/strong><\/p>\n\n\n\n<p>\u662f\u7684\uff0c\u53ef\u4ee5\u5728\u540c\u4e00\u5f20\u8868\u4e2d\u6df7\u5408\u4f7f\u7528char\u548cvarchar\uff0c\u6839\u636e\u9700\u8981\u9009\u62e9\u5408\u9002\u7684\u6570\u636e\u7c7b\u578b\u6765\u5b58\u50a8\u4e0d\u540c\u7684\u5b57\u6bb5\u3002\u8fd9\u6709\u52a9\u4e8e\u5728\u6570\u636e\u5e93\u8bbe\u8ba1\u4e2d\u66f4\u597d\u5730\u5e73\u8861\u5b58\u50a8\u6548\u7387\u548c\u6027\u80fd\u8981\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"char\u548cvarchar\u662f\u5728\u6570\u636e\u5e93\u4e2d\u5e38\u7528\u7684\u4e24\u79cd\u6570\u636e\u7c7b\u578b\uff0c\u5b83\u4eec\u4e4b\u95f4\u5b58\u5728\u4e00\u4e9b\u91cd\u8981\u7684\u533a\u522b\u3002\u672c\u6587\u5c06\u6df1\u5165\u63a2\u8ba8char\u548cv [&hellip;]","protected":false},"author":5,"featured_media":66629,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/66624"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=66624"}],"version-history":[{"count":0,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/66624\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/66629"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=66624"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=66624"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=66624"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}