{"id":60655,"date":"2024-10-13T04:41:16","date_gmt":"2024-10-12T20:41:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/60655\/"},"modified":"2024-10-13T04:41:16","modified_gmt":"2024-10-12T20:41:16","slug":"db2%e6%95%b8%e6%93%9a%e5%ba%absql%e7%b7%a8%e5%af%ab%e6%8a%80%e5%b7%a7%e5%88%86%e4%ba%ab-db2%e6%95%b8%e6%93%9a%e5%ba%ab%e5%af%absql%e8%aa%9e%e5%8f%a5","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/60655\/","title":{"rendered":"DB2\u6578\u64da\u5eabSQL\u7de8\u5beb\u6280\u5de7\u5206\u4eab (db2\u6578\u64da\u5eab\u5bebsql\u8a9e\u53e5)"},"content":{"rendered":"<h1 id=\"db2%e6%95%b8%e6%93%9a%e5%ba%absql%e7%b7%a8%e5%af%ab%e6%8a%80%e5%b7%a7%e5%88%86%e4%ba%ab-sQfQKVshWR\">DB2\u6578\u64da\u5eabSQL\u7de8\u5beb\u6280\u5de7\u5206\u4eab<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff08DBMS\uff09\u626e\u6f14\u8457\u81f3\u95dc\u91cd\u8981\u7684\u89d2\u8272\u3002IBM\u7684DB2\u6578\u64da\u5eab\u662f\u4e00\u500b\u5f37\u5927\u7684\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u4f01\u696d\u7d1a\u61c9\u7528\u4e2d\u3002\u672c\u6587\u5c07\u5206\u4eab\u4e00\u4e9bDB2\u6578\u64da\u5eabSQL\u7de8\u5beb\u7684\u6280\u5de7\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u9ad8\u6548\u5730\u64b0\u5bebSQL\u8a9e\u53e5\u3002<\/p>\n<h2 id=\"1-%e7%90%86%e8%a7%a3db2%e7%9a%84%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-sQfQKVshWR\">1. \u7406\u89e3DB2\u7684\u6578\u64da\u985e\u578b<\/h2>\n<p>\u5728\u7de8\u5bebSQL\u8a9e\u53e5\u4e4b\u524d\uff0c\u9996\u5148\u9700\u8981\u4e86\u89e3DB2\u652f\u6301\u7684\u6578\u64da\u985e\u578b\u3002DB2\u63d0\u4f9b\u4e86\u591a\u7a2e\u6578\u64da\u985e\u578b\uff0c\u5305\u62ec\u6574\u6578\u3001\u6d6e\u9ede\u6578\u3001\u5b57\u7b26\u3001\u65e5\u671f\u548c\u6642\u9593\u7b49\u3002\u6b63\u78ba\u9078\u64c7\u6578\u64da\u985e\u578b\u4e0d\u50c5\u80fd\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u9084\u80fd\u6e1b\u5c11\u5b58\u5132\u7a7a\u9593\u7684\u6d6a\u8cbb\u3002<\/p>\n<ul>\n<li><code>INTEGER<\/code>\uff1a\u7528\u65bc\u5b58\u5132\u6574\u6578\u3002<\/li>\n<li><code>DECIMAL(p,s)<\/code>\uff1a\u7528\u65bc\u5b58\u5132\u7cbe\u78ba\u7684\u5341\u9032\u5236\u6578\u3002<\/li>\n<li><code>VARCHAR(n)<\/code>\uff1a\u7528\u65bc\u5b58\u5132\u53ef\u8b8a\u9577\u5ea6\u7684\u5b57\u7b26\u4e32\u3002<\/li>\n<li><code>DATE<\/code>\uff1a\u7528\u65bc\u5b58\u5132\u65e5\u671f\u3002<\/li>\n<\/ul>\n<h2 id=\"2-%e4%bd%bf%e7%94%a8%e7%b4%a2%e5%bc%95%e6%8f%90%e9%ab%98%e6%9f%a5%e8%a9%a2%e6%80%a7%e8%83%bd-sQfQKVshWR\">2. \u4f7f\u7528\u7d22\u5f15\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd<\/h2>\n<p>\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u91cd\u8981\u5de5\u5177\u3002\u5728DB2\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528<code>CREATE INDEX<\/code>\u8a9e\u53e5\u5275\u5efa\u7d22\u5f15\u3002\u7d22\u5f15\u53ef\u4ee5\u52a0\u901f\u67e5\u8a62\uff0c\u4f46\u4e5f\u6703\u589e\u52a0\u6578\u64da\u63d2\u5165\u548c\u66f4\u65b0\u7684\u6210\u672c\uff0c\u56e0\u6b64\u9700\u8981\u6839\u64da\u5be6\u969b\u60c5\u6cc1\u5408\u7406\u4f7f\u7528\u3002<\/p>\n<pre><code>CREATE INDEX idx_employee_name ON employees(name);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u70ba<code>employees<\/code>\u8868\u7684<code>name<\/code>\u5217\u5275\u5efa\u4e86\u4e00\u500b\u7d22\u5f15\uff0c\u9019\u6a23\u5728\u67e5\u8a62\u6642\u53ef\u4ee5\u66f4\u5feb\u5730\u627e\u5230\u76f8\u95dc\u8a18\u9304\u3002<\/p>\n<h2 id=\"3-%e4%bd%bf%e7%94%a8join%e5%84%aa%e5%8c%96%e6%9f%a5%e8%a9%a2-sQfQKVshWR\">3. \u4f7f\u7528JOIN\u512a\u5316\u67e5\u8a62<\/h2>\n<p>\u5728DB2\u4e2d\uff0c\u4f7f\u7528<code>JOIN<\/code>\u8a9e\u53e5\u53ef\u4ee5\u5c07\u591a\u500b\u8868\u7684\u6578\u64da\u7d50\u5408\u5728\u4e00\u8d77\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u91cd\u8907\u6578\u64da\uff0c\u63d0\u9ad8\u6578\u64da\u7684\u6574\u9ad4\u4e00\u81f4\u6027\u3002DB2\u652f\u6301\u591a\u7a2eJOIN\u985e\u578b\uff0c\u5305\u62ecINNER JOIN\u3001LEFT JOIN\u548cRIGHT JOIN\u7b49\u3002<\/p>\n<pre><code>SELECT e.name, d.department_name \nFROM employees e \nINNER JOIN departments d ON e.department_id = d.id;<\/code><\/pre>\n<p>\u4e0a\u8ff0\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u54e1\u5de5\u53ca\u5176\u6240\u5c6c\u90e8\u9580\u7684\u540d\u7a31\uff0c\u4f7f\u7528INNER JOIN\u53ef\u4ee5\u78ba\u4fdd\u53ea\u8fd4\u56de\u90a3\u4e9b\u5728\u5169\u500b\u8868\u4e2d\u90fd\u6709\u7684\u8a18\u9304\u3002<\/p>\n<h2 id=\"4-%e4%bd%bf%e7%94%a8%e5%ad%90%e6%9f%a5%e8%a9%a2-sQfQKVshWR\">4. \u4f7f\u7528\u5b50\u67e5\u8a62<\/h2>\n<p>\u5b50\u67e5\u8a62\u662f\u6307\u5728\u4e00\u500b\u67e5\u8a62\u4e2d\u5d4c\u5957\u53e6\u4e00\u500b\u67e5\u8a62\u3002\u9019\u5728\u9700\u8981\u6839\u64da\u67d0\u4e9b\u689d\u4ef6\u904e\u6ffe\u6578\u64da\u6642\u975e\u5e38\u6709\u7528\u3002DB2\u652f\u6301\u5728SELECT\u3001INSERT\u3001UPDATE\u548cDELETE\u8a9e\u53e5\u4e2d\u4f7f\u7528\u5b50\u67e5\u8a62\u3002<\/p>\n<pre><code>SELECT name \nFROM employees \nWHERE department_id IN (SELECT id FROM departments WHERE location = 'Hong Kong');<\/code><\/pre>\n<p>\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u5728\u9999\u6e2f\u5730\u5340\u5de5\u4f5c\u7684\u54e1\u5de5\u7684\u59d3\u540d\u3002<\/p>\n<h2 id=\"5-%e4%bd%bf%e7%94%a8%e4%ba%8b%e5%8b%99%e7%ae%a1%e7%90%86%e6%95%b8%e6%93%9a%e4%b8%80%e8%87%b4%e6%80%a7-sQfQKVshWR\">5. \u4f7f\u7528\u4e8b\u52d9\u7ba1\u7406\u6578\u64da\u4e00\u81f4\u6027<\/h2>\n<p>\u5728DB2\u4e2d\uff0c\u4e8b\u52d9\u662f\u6307\u4e00\u7d44\u64cd\u4f5c\u7684\u96c6\u5408\uff0c\u9019\u4e9b\u64cd\u4f5c\u8981\u9ebc\u5168\u90e8\u6210\u529f\uff0c\u8981\u9ebc\u5168\u90e8\u5931\u6557\u3002\u4f7f\u7528<code>COMMIT<\/code>\u548c<code>ROLLBACK<\/code>\u8a9e\u53e5\u53ef\u4ee5\u7ba1\u7406\u4e8b\u52d9\uff0c\u78ba\u4fdd\u6578\u64da\u7684\u4e00\u81f4\u6027\u3002<\/p>\n<pre><code>BEGIN;\nUPDATE employees SET salary = salary * 1.1 WHERE performance = 'excellent';\nCOMMIT;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u5c07\u6240\u6709\u8868\u73fe\u512a\u79c0\u7684\u54e1\u5de5\u7684\u85aa\u6c34\u63d0\u9ad810%\u3002\u5982\u679c\u5728\u66f4\u65b0\u904e\u7a0b\u4e2d\u51fa\u73fe\u932f\u8aa4\uff0c\u53ef\u4ee5\u4f7f\u7528<code>ROLLBACK<\/code>\u4f86\u64a4\u92b7\u6240\u6709\u64cd\u4f5c\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-sQfQKVshWR\">\u7e3d\u7d50<\/h2>\n<p>\u638c\u63e1DB2\u6578\u64da\u5eab\u7684SQL\u7de8\u5beb\u6280\u5de7\u5c0d\u65bc\u958b\u767c\u8005\u4f86\u8aaa\u81f3\u95dc\u91cd\u8981\u3002\u901a\u904e\u7406\u89e3\u6578\u64da\u985e\u578b\u3001\u4f7f\u7528\u7d22\u5f15\u3001JOIN\u3001\u5b50\u67e5\u8a62\u548c\u4e8b\u52d9\u7ba1\u7406\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u6578\u64da\u64cd\u4f5c\u7684\u6548\u7387\u548c\u5b89\u5168\u6027\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u4f01\u696d\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u53ef\u9760\u7684<code><a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a><\/code>\u6216<code><a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a><\/code>\uff0cServer.HK\u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22DB2\u6578\u64da\u5eab\u7684SQL\u7de8\u5beb\u6280\u5de7\uff0c\u63d0\u5347\u67e5\u8a62\u6548\u7387\uff0c\u512a\u5316\u6027\u80fd\uff0c\u8b93\u6578\u64da\u7ba1\u7406\u66f4\u8f15\u9b06\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-60655","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60655","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=60655"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60655\/revisions"}],"predecessor-version":[{"id":60656,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60655\/revisions\/60656"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=60655"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=60655"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=60655"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}