{"id":179332,"date":"2024-11-09T00:56:19","date_gmt":"2024-11-08T16:56:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/179332\/"},"modified":"2024-11-09T00:56:20","modified_gmt":"2024-11-08T16:56:20","slug":"%e5%a6%82%e4%bd%95%e7%94%a8-sql-%e4%bf%ae%e6%94%b9%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ad%97%e6%ae%b5%e9%95%b7%e5%ba%a6-%e4%bf%ae%e6%94%b9%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ad%97%e6%ae%b5%e9%95%b7%e5%ba%a6-sql","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/179332\/","title":{"rendered":"\u5982\u4f55\u7528 SQL \u4fee\u6539\u6578\u64da\u5eab\u5b57\u6bb5\u9577\u5ea6 (\u4fee\u6539\u6578\u64da\u5eab\u5b57\u6bb5\u9577\u5ea6 sql \u8a9e\u53e5)"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e7%94%a8-sql-%e4%bf%ae%e6%94%b9%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ad%97%e6%ae%b5%e9%95%b7%e5%ba%a6-OkhofbJIOd\">\u5982\u4f55\u7528 SQL \u4fee\u6539\u6578\u64da\u5eab\u5b57\u6bb5\u9577\u5ea6<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u96a8\u8457\u696d\u52d9\u9700\u6c42\u7684\u8b8a\u5316\uff0c\u53ef\u80fd\u9700\u8981\u8abf\u6574\u6578\u64da\u5eab\u5b57\u6bb5\u7684\u9577\u5ea6\u3002\u9019\u7bc7\u6587\u7ae0\u5c07\u4ecb\u7d39\u5982\u4f55\u4f7f\u7528 SQL \u8a9e\u53e5\u4f86\u4fee\u6539\u6578\u64da\u5eab\u5b57\u6bb5\u7684\u9577\u5ea6\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u7bc4\u4f8b\u548c\u6ce8\u610f\u4e8b\u9805\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e5%ad%97%e6%ae%b5%e9%95%b7%e5%ba%a6%ef%bc%9f-OkhofbJIOd\">\u4ec0\u9ebc\u662f\u5b57\u6bb5\u9577\u5ea6\uff1f<\/h2>\n<p>\u5b57\u6bb5\u9577\u5ea6\u662f\u6307\u6578\u64da\u5eab\u4e2d\u67d0\u4e00\u5b57\u6bb5\u6240\u80fd\u5b58\u5132\u7684\u6578\u64da\u7684\u6700\u5927\u5b57\u5143\u6578\u3002\u4e0d\u540c\u7684\u6578\u64da\u985e\u578b\u6709\u4e0d\u540c\u7684\u5b57\u6bb5\u9577\u5ea6\u9650\u5236\u3002\u4f8b\u5982\uff0cVARCHAR \u985e\u578b\u7684\u5b57\u6bb5\u53ef\u4ee5\u5b58\u5132\u53ef\u8b8a\u9577\u5ea6\u7684\u5b57\u4e32\uff0c\u800c CHAR \u985e\u578b\u7684\u5b57\u6bb5\u5247\u662f\u56fa\u5b9a\u9577\u5ea6\u7684\u5b57\u4e32\u3002\u7576\u696d\u52d9\u9700\u6c42\u8b8a\u66f4\u6642\uff0c\u53ef\u80fd\u9700\u8981\u589e\u52a0\u6216\u6e1b\u5c11\u5b57\u6bb5\u7684\u9577\u5ea6\u3002<\/p>\n<h2 id=\"%e4%bf%ae%e6%94%b9%e5%ad%97%e6%ae%b5%e9%95%b7%e5%ba%a6%e7%9a%84-sql-%e8%aa%9e%e5%8f%a5-OkhofbJIOd\">\u4fee\u6539\u5b57\u6bb5\u9577\u5ea6\u7684 SQL \u8a9e\u53e5<\/h2>\n<p>\u5728 SQL \u4e2d\uff0c\u4fee\u6539\u5b57\u6bb5\u9577\u5ea6\u901a\u5e38\u4f7f\u7528 ALTER TABLE \u8a9e\u53e5\u3002\u4ee5\u4e0b\u662f\u57fa\u672c\u7684\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE \u8868\u540d MODIFY COLUMN \u5b57\u6bb5\u540d \u6578\u64da\u985e\u578b(\u65b0\u9577\u5ea6);<\/code><\/pre>\n<p>\u9019\u88e1\u7684\u201c\u8868\u540d\u201d\u662f\u4f60\u8981\u4fee\u6539\u7684\u8868\u7684\u540d\u7a31\uff0c\u201c\u5b57\u6bb5\u540d\u201d\u662f\u4f60\u8981\u4fee\u6539\u7684\u5b57\u6bb5\u540d\u7a31\uff0c\u201c\u6578\u64da\u985e\u578b\u201d\u662f\u8a72\u5b57\u6bb5\u7684\u6578\u64da\u985e\u578b\uff0c\u800c\u201c\u65b0\u9577\u5ea6\u201d\u5247\u662f\u4f60\u5e0c\u671b\u8a2d\u7f6e\u7684\u65b0\u9577\u5ea6\u3002<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b-OkhofbJIOd\">\u7bc4\u4f8b<\/h3>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>users<\/code> \u7684\u8868\uff0c\u88e1\u9762\u6709\u4e00\u500b\u540d\u70ba <code>username<\/code> \u7684\u5b57\u6bb5\uff0c\u7576\u524d\u7684\u6578\u64da\u985e\u578b\u70ba <code>VARCHAR(50)<\/code>\u3002\u5982\u679c\u6211\u5011\u5e0c\u671b\u5c07\u9019\u500b\u5b57\u6bb5\u7684\u9577\u5ea6\u589e\u52a0\u5230 100\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u8a9e\u53e5\uff1a<\/p>\n<pre><code>ALTER TABLE users MODIFY COLUMN username VARCHAR(100);<\/code><\/pre>\n<p>\u9019\u689d\u8a9e\u53e5\u5c07 <code>username<\/code> \u5b57\u6bb5\u7684\u6700\u5927\u9577\u5ea6\u5f9e 50 \u589e\u52a0\u5230 100\u3002<\/p>\n<h3 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-OkhofbJIOd\">\u6ce8\u610f\u4e8b\u9805<\/h3>\n<ul>\n<li><strong>\u6578\u64da\u5b8c\u6574\u6027\uff1a<\/strong>\u5728\u4fee\u6539\u5b57\u6bb5\u9577\u5ea6\u4e4b\u524d\uff0c\u8acb\u78ba\u4fdd\u73fe\u6709\u6578\u64da\u4e0d\u6703\u56e0\u70ba\u65b0\u9577\u5ea6\u7684\u9650\u5236\u800c\u4e1f\u5931\u3002\u4f8b\u5982\uff0c\u5c07 <code>VARCHAR(50)<\/code> \u4fee\u6539\u70ba <code>VARCHAR(30)<\/code> \u53ef\u80fd\u6703\u5c0e\u81f4\u6578\u64da\u622a\u65b7\u3002<\/li>\n<li><strong>\u6578\u64da\u5eab\u9396\u5b9a\uff1a<\/strong>\u57f7\u884c ALTER TABLE \u8a9e\u53e5\u6642\uff0c\u6578\u64da\u5eab\u53ef\u80fd\u6703\u9396\u5b9a\u8a72\u8868\uff0c\u9019\u53ef\u80fd\u6703\u5f71\u97ff\u5176\u4ed6\u64cd\u4f5c\u3002\u56e0\u6b64\uff0c\u5efa\u8b70\u5728\u4f4e\u5cf0\u6642\u6bb5\u9032\u884c\u6b64\u985e\u64cd\u4f5c\u3002<\/li>\n<li><strong>\u5099\u4efd\u6578\u64da\uff1a<\/strong>\u5728\u9032\u884c\u4efb\u4f55\u7d50\u69cb\u6027\u8b8a\u66f4\u4e4b\u524d\uff0c\u52d9\u5fc5\u5099\u4efd\u6578\u64da\uff0c\u4ee5\u9632\u6b62\u610f\u5916\u60c5\u6cc1\u5c0e\u81f4\u6578\u64da\u4e1f\u5931\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-OkhofbJIOd\">\u7d50\u8ad6<\/h2>\n<p>\u4fee\u6539\u6578\u64da\u5eab\u5b57\u6bb5\u7684\u9577\u5ea6\u662f\u4e00\u500b\u76f8\u5c0d\u7c21\u55ae\u7684\u904e\u7a0b\uff0c\u4f46\u9700\u8981\u8b39\u614e\u64cd\u4f5c\u3002\u901a\u904e\u4f7f\u7528 <code>ALTER TABLE<\/code> \u8a9e\u53e5\uff0c\u60a8\u53ef\u4ee5\u9748\u6d3b\u5730\u8abf\u6574\u5b57\u6bb5\u7684\u9577\u5ea6\u4ee5\u6eff\u8db3\u696d\u52d9\u9700\u6c42\u3002\u5728\u9032\u884c\u6b64\u985e\u64cd\u4f5c\u6642\uff0c\u8acb\u52d9\u5fc5\u8003\u616e\u6578\u64da\u5b8c\u6574\u6027\u548c\u6578\u64da\u5eab\u6027\u80fd\u3002<\/p>\n<p>\u5982\u679c\u60a8\u9700\u8981\u66f4\u591a\u6709\u95dc\u6578\u64da\u5eab\u7ba1\u7406\u7684\u8cc7\u8a0a\uff0c\u6216\u662f\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4ee5\u7372\u53d6\u66f4\u591a\u8a73\u7d30\u8cc7\u8a0a\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2\u5982\u4f55\u4f7f\u7528 SQL \u8a9e\u53e5\u4fee\u6539\u6578\u64da\u5eab\u5b57\u6bb5\u9577\u5ea6\uff0c\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\u8207\u9748\u6d3b\u6027\uff0c\u7c21\u5316\u6578\u64da\u7ba1\u7406\u904e\u7a0b\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-179332","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179332","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=179332"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179332\/revisions"}],"predecessor-version":[{"id":179333,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/179332\/revisions\/179333"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=179332"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=179332"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=179332"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}