{"id":168447,"date":"2024-11-06T12:27:29","date_gmt":"2024-11-06T04:27:29","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168447\/"},"modified":"2024-11-06T12:27:30","modified_gmt":"2024-11-06T04:27:30","slug":"sql-%e8%aa%9e%e5%8f%a5%e5%89%b5%e5%bb%ba%e8%a1%a8%e6%99%82%e7%b5%a6%e5%88%97%e6%b7%bb%e5%8a%a0%e6%8c%87%e5%ae%9a%e8%aa%aa%e6%98%8e%e7%9a%84%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168447\/","title":{"rendered":"SQL \u8a9e\u53e5\u5275\u5efa\u8868\u6642\u7d66\u5217\u6dfb\u52a0\u6307\u5b9a\u8aaa\u660e\u7684\u65b9\u6cd5"},"content":{"rendered":"<h1 id=\"sql-%e8%aa%9e%e5%8f%a5%e5%89%b5%e5%bb%ba%e8%a1%a8%e6%99%82%e7%b5%a6%e5%88%97%e6%b7%bb%e5%8a%a0%e6%8c%87%e5%ae%9a%e8%aa%aa%e6%98%8e%e7%9a%84%e6%96%b9%e6%b3%95-HgjejIqvRX\">SQL \u8a9e\u53e5\u5275\u5efa\u8868\u6642\u7d66\u5217\u6dfb\u52a0\u6307\u5b9a\u8aaa\u660e\u7684\u65b9\u6cd5<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0cSQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u4e00\u7a2e\u81f3\u95dc\u91cd\u8981\u7684\u5de5\u5177\u3002\u7576\u6211\u5011\u5275\u5efa\u6578\u64da\u8868\u6642\uff0c\u9664\u4e86\u5b9a\u7fa9\u5217\u7684\u6578\u64da\u985e\u578b\u548c\u7d04\u675f\u689d\u4ef6\u5916\uff0c\u70ba\u5217\u6dfb\u52a0\u8aaa\u660e\uff08\u6216\u8a3b\u91cb\uff09\u4e5f\u662f\u4e00\u500b\u91cd\u8981\u7684\u6b65\u9a5f\u3002\u9019\u4e0d\u50c5\u6709\u52a9\u65bc\u63d0\u9ad8\u6578\u64da\u8868\u7684\u53ef\u8b80\u6027\uff0c\u9084\u80fd\u5728\u5718\u968a\u5354\u4f5c\u4e2d\u63d0\u4f9b\u6e05\u6670\u7684\u4e0a\u4e0b\u6587\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u5728 SQL \u8a9e\u53e5\u4e2d\u70ba\u5217\u6dfb\u52a0\u6307\u5b9a\u8aaa\u660e\u7684\u65b9\u6cd5\u3002<\/p>\n<h2 id=\"%e7%82%ba%e5%88%97%e6%b7%bb%e5%8a%a0%e8%aa%aa%e6%98%8e%e7%9a%84%e5%9f%ba%e6%9c%ac%e8%aa%9e%e6%b3%95-HgjejIqvRX\">\u70ba\u5217\u6dfb\u52a0\u8aaa\u660e\u7684\u57fa\u672c\u8a9e\u6cd5<\/h2>\n<p>\u5728 SQL \u4e2d\uff0c\u70ba\u5217\u6dfb\u52a0\u8aaa\u660e\u7684\u8a9e\u6cd5\u901a\u5e38\u662f\u4f7f\u7528 <code>COMMENT<\/code> \u95dc\u9375\u5b57\u3002\u9019\u500b\u95dc\u9375\u5b57\u53ef\u4ee5\u5728\u5275\u5efa\u8868\u7684\u904e\u7a0b\u4e2d\u76f4\u63a5\u4f7f\u7528\u3002\u4ee5\u4e0b\u662f\u57fa\u672c\u7684\u8a9e\u6cd5\u7d50\u69cb\uff1a<\/p>\n<pre><code>CREATE TABLE \u8868\u540d (\n    \u5217\u540d1 \u6578\u64da\u985e\u578b [\u7d04\u675f\u689d\u4ef6] COMMENT '\u5217\u7684\u8aaa\u660e',\n    \u5217\u540d2 \u6578\u64da\u985e\u578b [\u7d04\u675f\u689d\u4ef6] COMMENT '\u5217\u7684\u8aaa\u660e',\n    ...\n);<\/code><\/pre>\n<h2 id=\"%e7%a4%ba%e4%be%8b%ef%bc%9a%e5%89%b5%e5%bb%ba%e4%b8%80%e5%80%8b%e5%b8%b6%e6%9c%89%e8%aa%aa%e6%98%8e%e7%9a%84%e6%95%b8%e6%93%9a%e8%a1%a8-HgjejIqvRX\">\u793a\u4f8b\uff1a\u5275\u5efa\u4e00\u500b\u5e36\u6709\u8aaa\u660e\u7684\u6578\u64da\u8868<\/h2>\n<p>\u5047\u8a2d\u6211\u5011\u8981\u5275\u5efa\u4e00\u500b\u7528\u65bc\u5b58\u5132\u7528\u6236\u4fe1\u606f\u7684\u6578\u64da\u8868\uff0c\u8868\u540d\u70ba <code>users<\/code>\uff0c\u6211\u5011\u5e0c\u671b\u70ba\u6bcf\u4e00\u5217\u6dfb\u52a0\u76f8\u61c9\u7684\u8aaa\u660e\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff1a<\/p>\n<pre><code>CREATE TABLE users (\n    id INT AUTO_INCREMENT PRIMARY KEY COMMENT '\u7528\u6236\u552f\u4e00\u6a19\u8b58',\n    username VARCHAR(50) NOT NULL COMMENT '\u7528\u6236\u540d',\n    email VARCHAR(100) NOT NULL COMMENT '\u96fb\u5b50\u90f5\u4ef6\u5730\u5740',\n    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT '\u5275\u5efa\u6642\u9593'\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u793a\u4f8b\u4e2d\uff0c\u6211\u5011\u70ba\u6bcf\u4e00\u5217\u90fd\u6dfb\u52a0\u4e86\u8aaa\u660e\uff0c\u9019\u6a23\u5728\u67e5\u770b\u6578\u64da\u8868\u7d50\u69cb\u6642\uff0c\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u90fd\u80fd\u5feb\u901f\u7406\u89e3\u6bcf\u4e00\u5217\u7684\u7528\u9014\u3002<\/p>\n<h2 id=\"%e6%9f%a5%e8%a9%a2%e5%88%97%e7%9a%84%e8%aa%aa%e6%98%8e-HgjejIqvRX\">\u67e5\u8a62\u5217\u7684\u8aaa\u660e<\/h2>\n<p>\u5728\u5275\u5efa\u4e86\u5e36\u6709\u8aaa\u660e\u7684\u6578\u64da\u8868\u5f8c\uff0c\u60a8\u53ef\u80fd\u6703\u60f3\u8981\u67e5\u8a62\u9019\u4e9b\u8aaa\u660e\u3002\u4e0d\u540c\u7684\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff08DBMS\uff09\u6709\u4e0d\u540c\u7684\u65b9\u6cd5\u4f86\u67e5\u8a62\u5217\u7684\u8aaa\u660e\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684 DBMS \u7684\u67e5\u8a62\u65b9\u6cd5\uff1a<\/p>\n<ul>\n<li><strong>MySQL:<\/strong> \u4f7f\u7528 <code>SHOW FULL COLUMNS FROM \u8868\u540d;<\/code> \u547d\u4ee4\u4f86\u67e5\u770b\u5217\u7684\u8a73\u7d30\u4fe1\u606f\uff0c\u5305\u62ec\u8aaa\u660e\u3002<\/li>\n<li><strong>PostgreSQL:<\/strong> \u4f7f\u7528 <code>SELECT col_description(oid, ordinal_position) FROM information_schema.columns WHERE table_name = '\u8868\u540d';<\/code> \u4f86\u7372\u53d6\u5217\u7684\u8aaa\u660e\u3002<\/li>\n<li><strong>Oracle:<\/strong> \u4f7f\u7528 <code>SELECT comments FROM user_col_comments WHERE table_name = '\u8868\u540d';<\/code> \u4f86\u67e5\u8a62\u5217\u7684\u8aaa\u660e\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%9b%b4%e6%96%b0%e5%88%97%e7%9a%84%e8%aa%aa%e6%98%8e-HgjejIqvRX\">\u66f4\u65b0\u5217\u7684\u8aaa\u660e<\/h2>\n<p>\u5982\u679c\u9700\u8981\u66f4\u65b0\u5df2\u5b58\u5728\u5217\u7684\u8aaa\u660e\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>ALTER TABLE<\/code> \u8a9e\u53e5\u3002\u4ee5\u4e0b\u662f\u66f4\u65b0\u5217\u8aaa\u660e\u7684\u57fa\u672c\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE \u8868\u540d MODIFY \u5217\u540d \u6578\u64da\u985e\u578b COMMENT '\u65b0\u7684\u5217\u7684\u8aaa\u660e';<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5982\u679c\u6211\u5011\u60f3\u8981\u66f4\u65b0 <code>username<\/code> \u5217\u7684\u8aaa\u660e\uff0c\u53ef\u4ee5\u9019\u6a23\u505a\uff1a<\/p>\n<pre><code>ALTER TABLE users MODIFY username VARCHAR(50) COMMENT '\u7528\u6236\u7684\u767b\u9304\u540d';<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-HgjejIqvRX\">\u7e3d\u7d50<\/h2>\n<p>\u5728 SQL \u4e2d\u70ba\u5217\u6dfb\u52a0\u8aaa\u660e\u662f\u4e00\u500b\u7c21\u55ae\u4f46\u91cd\u8981\u7684\u6b65\u9a5f\uff0c\u9019\u4e0d\u50c5\u80fd\u63d0\u9ad8\u6578\u64da\u8868\u7684\u53ef\u8b80\u6027\uff0c\u9084\u80fd\u5e6b\u52a9\u5718\u968a\u6210\u54e1\u66f4\u597d\u5730\u7406\u89e3\u6578\u64da\u7d50\u69cb\u3002\u901a\u904e\u4f7f\u7528 <code>COMMENT<\/code> \u95dc\u9375\u5b57\uff0c\u6211\u5011\u53ef\u4ee5\u5728\u5275\u5efa\u8868\u6642\u8f15\u9b06\u5730\u70ba\u6bcf\u4e00\u5217\u6dfb\u52a0\u8aaa\u660e\uff0c\u4e26\u4e14\u53ef\u4ee5\u96a8\u6642\u67e5\u8a62\u548c\u66f4\u65b0\u9019\u4e9b\u8aaa\u660e\u3002\u5c0d\u65bc\u9700\u8981\u7ba1\u7406\u5927\u91cf\u6578\u64da\u7684\u4f01\u696d\u4f86\u8aaa\uff0c\u9019\u7a2e\u505a\u6cd5\u5c24\u70ba\u91cd\u8981\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u652f\u6301\u60a8\u7684\u6578\u64da\u5eab\u7ba1\u7406\u9700\u6c42\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u5e6b\u52a9\u60a8\u8f15\u9b06\u7ba1\u7406\u548c\u64f4\u5c55\u60a8\u7684\u696d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u5982\u4f55\u5728 SQL \u8a9e\u53e5\u4e2d\u5275\u5efa\u8868\u6642\u70ba\u5217\u6dfb\u52a0\u6307\u5b9a\u8aaa\u660e\uff0c\u63d0\u5347\u6578\u64da\u5eab\u7d50\u69cb\u7684\u53ef\u8b80\u6027\u8207\u7dad\u8b77\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-168447","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168447","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=168447"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168447\/revisions"}],"predecessor-version":[{"id":168448,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168447\/revisions\/168448"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168447"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168447"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168447"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}