{"id":180392,"date":"2024-11-09T09:53:18","date_gmt":"2024-11-09T01:53:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/180392\/"},"modified":"2024-11-09T09:53:19","modified_gmt":"2024-11-09T01:53:19","slug":"%e6%b7%b1%e5%ba%a6%e5%88%86%e6%9e%90db2%e4%bf%ae%e6%94%b9%e8%a1%a8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/180392\/","title":{"rendered":"\u6df1\u5ea6\u5206\u6790DB2\u4fee\u6539\u8868"},"content":{"rendered":"<h1 id=\"%e6%b7%b1%e5%ba%a6%e5%88%86%e6%9e%90db2%e4%bf%ae%e6%94%b9%e8%a1%a8-mTGdUeMOUF\">\u6df1\u5ea6\u5206\u6790DB2\u4fee\u6539\u8868<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u8868\u683c\u662f\u5b58\u5132\u6578\u64da\u7684\u57fa\u672c\u55ae\u4f4d\u3002IBM\u7684DB2\u662f\u4e00\u500b\u5f37\u5927\u7684\u95dc\u806f\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u4f01\u696d\u74b0\u5883\u4e2d\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u5982\u4f55\u5728DB2\u4e2d\u4fee\u6539\u8868\u683c\uff0c\u5305\u62ec\u4fee\u6539\u8868\u7d50\u69cb\u3001\u6dfb\u52a0\u6216\u522a\u9664\u5217\u3001\u4ee5\u53ca\u66f4\u65b0\u7d04\u675f\u689d\u4ef6\u7b49\u64cd\u4f5c\u3002<\/p>\n<h2 id=\"db2%e4%bf%ae%e6%94%b9%e8%a1%a8%e7%9a%84%e5%9f%ba%e6%9c%ac%e8%aa%9e%e6%b3%95-mTGdUeMOUF\">DB2\u4fee\u6539\u8868\u7684\u57fa\u672c\u8a9e\u6cd5<\/h2>\n<p>\u5728DB2\u4e2d\uff0c\u4fee\u6539\u8868\u7684\u4e3b\u8981\u8a9e\u6cd5\u662f\u4f7f\u7528ALTER TABLE\u8a9e\u53e5\u3002\u9019\u500b\u8a9e\u53e5\u5141\u8a31\u7528\u6236\u5c0d\u73fe\u6709\u7684\u8868\u9032\u884c\u591a\u7a2e\u64cd\u4f5c\u3002\u4ee5\u4e0b\u662fALTER TABLE\u7684\u57fa\u672c\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE table_name\n    {ADD column_name data_type [constraint],\n     DROP column_name,\n     ALTER COLUMN column_name SET DATA TYPE new_data_type,\n     ADD CONSTRAINT constraint_name constraint_type (column_name),\n     DROP CONSTRAINT constraint_name};<\/code><\/pre>\n<h2 id=\"%e4%bf%ae%e6%94%b9%e8%a1%a8%e7%b5%90%e6%a7%8b-mTGdUeMOUF\">\u4fee\u6539\u8868\u7d50\u69cb<\/h2>\n<h3 id=\"%e6%b7%bb%e5%8a%a0%e6%96%b0%e5%88%97-mTGdUeMOUF\">\u6dfb\u52a0\u65b0\u5217<\/h3>\n<p>\u5982\u679c\u9700\u8981\u5728\u73fe\u6709\u8868\u4e2d\u6dfb\u52a0\u65b0\u5217\uff0c\u53ef\u4ee5\u4f7f\u7528ADD\u5b50\u53e5\u3002\u4f8b\u5982\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba\u201cemployees\u201d\u7684\u8868\uff0c\u4e26\u5e0c\u671b\u6dfb\u52a0\u4e00\u500b\u201cbirthdate\u201d\u5217\uff1a<\/p>\n<pre><code>ALTER TABLE employees\n    ADD birthdate DATE;<\/code><\/pre>\n<h3 id=\"%e5%88%aa%e9%99%a4%e5%88%97-mTGdUeMOUF\">\u522a\u9664\u5217<\/h3>\n<p>\u82e5\u8981\u522a\u9664\u4e00\u500b\u4e0d\u518d\u9700\u8981\u7684\u5217\uff0c\u53ef\u4ee5\u4f7f\u7528DROP\u5b50\u53e5\u3002\u4ee5\u4e0b\u662f\u522a\u9664\u201cbirthdate\u201d\u5217\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>ALTER TABLE employees\n    DROP COLUMN birthdate;<\/code><\/pre>\n<h3 id=\"%e4%bf%ae%e6%94%b9%e5%88%97%e7%9a%84%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-mTGdUeMOUF\">\u4fee\u6539\u5217\u7684\u6578\u64da\u985e\u578b<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u53ef\u80fd\u9700\u8981\u66f4\u6539\u5217\u7684\u6578\u64da\u985e\u578b\u3002\u9019\u53ef\u4ee5\u901a\u904eALTER COLUMN\u5b50\u53e5\u4f86\u5be6\u73fe\u3002\u4f8b\u5982\uff0c\u5c07\u201csalary\u201d\u5217\u7684\u6578\u64da\u985e\u578b\u5f9eINTEGER\u66f4\u6539\u70baDECIMAL\uff1a<\/p>\n<pre><code>ALTER TABLE employees\n    ALTER COLUMN salary SET DATA TYPE DECIMAL(10, 2);<\/code><\/pre>\n<h2 id=\"%e6%9b%b4%e6%96%b0%e7%b4%84%e6%9d%9f%e6%a2%9d%e4%bb%b6-mTGdUeMOUF\">\u66f4\u65b0\u7d04\u675f\u689d\u4ef6<\/h2>\n<p>\u5728DB2\u4e2d\uff0c\u7d04\u675f\u689d\u4ef6\u7528\u65bc\u78ba\u4fdd\u6578\u64da\u7684\u5b8c\u6574\u6027\u3002\u53ef\u4ee5\u4f7f\u7528ALTER TABLE\u8a9e\u53e5\u4f86\u6dfb\u52a0\u6216\u522a\u9664\u7d04\u675f\u689d\u4ef6\u3002\u4f8b\u5982\uff0c\u70ba\u201cemployees\u201d\u8868\u7684\u201cemail\u201d\u5217\u6dfb\u52a0\u552f\u4e00\u7d04\u675f\uff1a<\/p>\n<pre><code>ALTER TABLE employees\n    ADD CONSTRAINT unique_email UNIQUE (email);<\/code><\/pre>\n<p>\u5982\u679c\u9700\u8981\u522a\u9664\u9019\u500b\u7d04\u675f\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u53e5\uff1a<\/p>\n<pre><code>ALTER TABLE employees\n    DROP CONSTRAINT unique_email;<\/code><\/pre>\n<h2 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TABLE\u8a9e\u53e5\uff0c\u4f7f\u5f97\u7528\u6236\u80fd\u5920\u65b9\u4fbf\u5730\u4fee\u6539\u8868\u7d50\u69cb\u3002\u7121\u8ad6\u662f\u6dfb\u52a0\u3001\u522a\u9664\u5217\uff0c\u9084\u662f\u66f4\u65b0\u7d04\u675f\u689d\u4ef6\uff0c\u9019\u4e9b\u64cd\u4f5c\u90fd\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u66f4\u597d\u5730\u7ba1\u7406\u6578\u64da\u5eab\u4e2d\u7684\u6578\u64da\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u7ba1\u7406\u7684\u4f01\u696d\u4f86\u8aaa\uff0c\u638c\u63e1\u9019\u4e9b\u57fa\u672c\u64cd\u4f5c\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u53ef\u9760\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK\u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u9700\u6c42\u7684\u5ba2\u6236\u3002\u7121\u8ad6\u662f\u6578\u64da\u5eab\u7ba1\u7406\u9084\u662f\u5176\u4ed6\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a> \u5c0d\u65bc\u696d\u52d9\u7684\u6210\u529f\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u5206\u6790DB2\u4fee\u6539\u8868\u7684\u6700\u4f73\u5b9e\u8df5\u4e0e\u6280\u5de7\uff0c\u5e2e\u52a9\u60a8\u9ad8\u6548\u7ba1\u7406\u6570\u636e\u5e93\u7ed3\u6784\uff0c\u63d0\u5347\u6027\u80fd\u4e0e\u6570\u636e\u4e00\u81f4\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-180392","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/180392","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=180392"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/180392\/revisions"}],"predecessor-version":[{"id":180393,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/180392\/revisions\/180393"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=180392"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=180392"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=180392"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}