{"id":182218,"date":"2024-11-09T21:05:22","date_gmt":"2024-11-09T13:05:22","guid":{"rendered":"https:\/\/server.hk\/cnblog\/182218\/"},"modified":"2024-11-09T21:05:23","modified_gmt":"2024-11-09T13:05:23","slug":"%e6%b7%b1%e5%85%a5%e6%8e%a2%e8%a8%8e%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%adalter%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95%ef%bc%88%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%adalter%e7%9a%84%e7%94%a8%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/182218\/","title":{"rendered":"\u6df1\u5165\u63a2\u8a0e\u6578\u64da\u5eab\u4e2dalter\u7684\u4f7f\u7528\u65b9\u6cd5\uff08\u6578\u64da\u5eab\u4e2dalter\u7684\u7528\u6cd5\uff09"},"content":{"rendered":"<h1 id=\"%e6%b7%b1%e5%85%a5%e6%8e%a2%e8%a8%8e%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%adalter%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95-mFVjIDEDJj\">\u6df1\u5165\u63a2\u8a0e\u6578\u64da\u5eab\u4e2dALTER\u7684\u4f7f\u7528\u65b9\u6cd5<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0cALTER\u8a9e\u53e5\u662f\u4e00\u500b\u975e\u5e38\u91cd\u8981\u7684\u5de5\u5177\u3002\u5b83\u5141\u8a31\u7528\u6236\u5c0d\u73fe\u6709\u7684\u6578\u64da\u5eab\u7d50\u69cb\u9032\u884c\u4fee\u6539\uff0c\u5305\u62ec\u8868\u7684\u7d50\u69cb\u3001\u7d22\u5f15\u3001\u7d04\u675f\u7b49\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eALTER\u7684\u4f7f\u7528\u65b9\u6cd5\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u969b\u7684\u793a\u4f8b\u4f86\u5e6b\u52a9\u7406\u89e3\u3002<\/p>\n<h2 id=\"alter%e8%aa%9e%e5%8f%a5%e7%9a%84%e5%9f%ba%e6%9c%ac%e8%aa%9e%e6%b3%95-mFVjIDEDJj\">ALTER\u8a9e\u53e5\u7684\u57fa\u672c\u8a9e\u6cd5<\/h2>\n<p>ALTER\u8a9e\u53e5\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>ALTER TABLE table_name action;<\/code><\/pre>\n<p>\u5176\u4e2d\uff0c<code>table_name<\/code>\u662f\u8981\u4fee\u6539\u7684\u8868\u7684\u540d\u7a31\uff0c\u800c<code>action<\/code>\u5247\u662f\u5177\u9ad4\u7684\u4fee\u6539\u64cd\u4f5c\u3002\u6839\u64da\u4e0d\u540c\u7684\u9700\u6c42\uff0cALTER\u8a9e\u53e5\u53ef\u4ee5\u7528\u4f86\u6dfb\u52a0\u3001\u522a\u9664\u6216\u4fee\u6539\u8868\u4e2d\u7684\u5217\u3002<\/p>\n<h2 id=\"%e5%b8%b8%e8%a6%8b%e7%9a%84alter%e6%93%8d%e4%bd%9c-mFVjIDEDJj\">\u5e38\u898b\u7684ALTER\u64cd\u4f5c<\/h2>\n<h3 id=\"1-%e6%b7%bb%e5%8a%a0%e5%88%97-mFVjIDEDJj\">1. \u6dfb\u52a0\u5217<\/h3>\n<p>\u4f7f\u7528ALTER TABLE\u8a9e\u53e5\u53ef\u4ee5\u8f15\u9b06\u5730\u5411\u8868\u4e2d\u6dfb\u52a0\u65b0\u5217\u3002\u4ee5\u4e0b\u662f\u6dfb\u52a0\u5217\u7684\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE table_name ADD column_name column_type;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba<code>employees<\/code>\u7684\u8868\uff0c\u6211\u5011\u60f3\u8981\u6dfb\u52a0\u4e00\u500b\u540d\u70ba<code>birthdate<\/code>\u7684\u5217\uff0c\u985e\u578b\u70ba\u65e5\u671f\uff1a<\/p>\n<pre><code>ALTER TABLE employees ADD birthdate DATE;<\/code><\/pre>\n<h3 id=\"2-%e5%88%aa%e9%99%a4%e5%88%97-mFVjIDEDJj\">2. \u522a\u9664\u5217<\/h3>\n<p>\u5982\u679c\u9700\u8981\u522a\u9664\u8868\u4e2d\u7684\u67d0\u4e00\u5217\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE table_name DROP COLUMN column_name;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5f9e<code>employees<\/code>\u8868\u4e2d\u522a\u9664<code>birthdate<\/code>\u5217\uff1a<\/p>\n<pre><code>ALTER TABLE employees DROP COLUMN birthdate;<\/code><\/pre>\n<h3 id=\"3-%e4%bf%ae%e6%94%b9%e5%88%97-mFVjIDEDJj\">3. \u4fee\u6539\u5217<\/h3>\n<p>ALTER\u8a9e\u53e5\u9084\u53ef\u4ee5\u7528\u4f86\u4fee\u6539\u73fe\u6709\u5217\u7684\u6578\u64da\u985e\u578b\u6216\u7d04\u675f\u3002\u4ee5\u4e0b\u662f\u4fee\u6539\u5217\u7684\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE table_name MODIFY column_name new_column_type;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5c07<code>employees<\/code>\u8868\u4e2d\u7684<code>salary<\/code>\u5217\u7684\u6578\u64da\u985e\u578b\u5f9e\u6574\u6578\u6539\u70ba\u6d6e\u9ede\u6578\uff1a<\/p>\n<pre><code>ALTER TABLE employees MODIFY salary FLOAT;<\/code><\/pre>\n<h3 id=\"4-%e6%b7%bb%e5%8a%a0%e7%b4%84%e6%9d%9f-mFVjIDEDJj\">4. \u6dfb\u52a0\u7d04\u675f<\/h3>\n<p>\u9664\u4e86\u4fee\u6539\u5217\u7684\u7d50\u69cb\uff0cALTER\u8a9e\u53e5\u9084\u53ef\u4ee5\u7528\u4f86\u6dfb\u52a0\u7d04\u675f\uff0c\u4f8b\u5982\u4e3b\u9375\u3001\u5916\u9375\u6216\u552f\u4e00\u7d04\u675f\u3002\u4ee5\u4e0b\u662f\u6dfb\u52a0\u4e3b\u9375\u7684\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE table_name ADD CONSTRAINT constraint_name PRIMARY KEY (column_name);<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u70ba<code>employees<\/code>\u8868\u4e2d\u7684<code>employee_id<\/code>\u5217\u6dfb\u52a0\u4e3b\u9375\u7d04\u675f\uff1a<\/p>\n<pre><code>ALTER TABLE employees ADD CONSTRAINT pk_employee_id PRIMARY KEY (employee_id);<\/code><\/pre>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-mFVjIDEDJj\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u5728\u4f7f\u7528ALTER\u8a9e\u53e5\u6642\uff0c\u6709\u5e7e\u9ede\u9700\u8981\u7279\u5225\u6ce8\u610f\uff1a<\/p>\n<ul>\n<li>\u5728\u9032\u884c\u7d50\u69cb\u4fee\u6539\u4e4b\u524d\uff0c\u5efa\u8b70\u5099\u4efd\u6578\u64da\uff0c\u4ee5\u9632\u6b62\u610f\u5916\u6578\u64da\u4e1f\u5931\u3002<\/li>\n<li>\u67d0\u4e9b\u6578\u64da\u5eab\u7cfb\u7d71\u5c0dALTER\u64cd\u4f5c\u7684\u652f\u6301\u7a0b\u5ea6\u4e0d\u540c\uff0c\u5177\u9ad4\u8a9e\u6cd5\u53ef\u80fd\u6703\u6709\u6240\u4e0d\u540c\u3002<\/li>\n<li>\u5728\u9ad8\u6d41\u91cf\u7684\u751f\u7522\u74b0\u5883\u4e2d\uff0cALTER\u64cd\u4f5c\u53ef\u80fd\u6703\u5c0e\u81f4\u9396\u5b9a\uff0c\u5f71\u97ff\u6027\u80fd\uff0c\u56e0\u6b64\u61c9\u8b39\u614e\u4f7f\u7528\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-mFVjIDEDJj\">\u7e3d\u7d50<\/h2>\n<p>ALTER\u8a9e\u53e5\u662f\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\u4e0d\u53ef\u6216\u7f3a\u7684\u4e00\u90e8\u5206\uff0c\u80fd\u5920\u9748\u6d3b\u5730\u5c0d\u6578\u64da\u5eab\u7d50\u69cb\u9032\u884c\u8abf\u6574\u3002\u7121\u8ad6\u662f\u6dfb\u52a0\u3001\u522a\u9664\u9084\u662f\u4fee\u6539\u5217\uff0c\u638c\u63e1ALTER\u7684\u4f7f\u7528\u65b9\u6cd5\u90fd\u80fd\u63d0\u9ad8\u6578\u64da\u5eab\u7ba1\u7406\u7684\u6548\u7387\u3002\u5c0d\u65bc\u9700\u8981\u7a69\u5b9a\u548c\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\u7684\u7528\u6236\uff0c\u9078\u64c7\u5408\u9069\u7684\u670d\u52d9\u63d0\u4f9b\u5546\u81f3\u95dc\u91cd\u8981\u3002\u82e5\u60a8\u5c0d\u65bc<code>VPS<\/code>\u3001<code>\u9999\u6e2fVPS<\/code>\u6216\u5176\u4ed6<code>\u4e91\u670d\u52a1\u5668<\/code>\u7684\u9700\u6c42\u6709\u8208\u8da3\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9 <a href=\"https:\/\/server.hk\">Server.HK<\/a> \u7372\u53d6\u66f4\u591a\u8cc7\u8a0a\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u63a2\u8a0e\u6578\u64da\u5eab\u4e2dALTER\u7684\u4f7f\u7528\u65b9\u6cd5\uff0c\u4e86\u89e3\u5982\u4f55\u4fee\u6539\u8868\u7d50\u69cb\u3001\u6dfb\u52a0\u6b04\u4f4d\u53ca\u66f4\u65b0\u7d04\u675f\uff0c\u63d0\u5347\u6578\u64da\u7ba1\u7406\u6548\u7387\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-182218","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/182218","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=182218"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/182218\/revisions"}],"predecessor-version":[{"id":182219,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/182218\/revisions\/182219"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=182218"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=182218"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=182218"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}