{"id":94642,"date":"2024-10-19T19:57:28","date_gmt":"2024-10-19T11:57:28","guid":{"rendered":"https:\/\/server.hk\/cnblog\/94642\/"},"modified":"2024-10-19T19:57:28","modified_gmt":"2024-10-19T11:57:28","slug":"oracle-%e8%aa%9e%e5%8f%a5%e7%9a%84%e5%84%aa%e5%8c%96%e8%a6%8f%e5%89%87%e4%b8%ad%e7%9a%84%e7%9b%b8%e9%97%9c%e9%a0%85%e7%9b%ae","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/94642\/","title":{"rendered":"Oracle \u8a9e\u53e5\u7684\u512a\u5316\u898f\u5247\u4e2d\u7684\u76f8\u95dc\u9805\u76ee"},"content":{"rendered":"<h1 id=\"oracle-%e8%aa%9e%e5%8f%a5%e7%9a%84%e5%84%aa%e5%8c%96%e8%a6%8f%e5%89%87%e4%b8%ad%e7%9a%84%e7%9b%b8%e9%97%9c%e9%a0%85%e7%9b%ae-AIvJGqOpvp\">Oracle \u8a9e\u53e5\u7684\u512a\u5316\u898f\u5247\u4e2d\u7684\u76f8\u95dc\u9805\u76ee<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u512a\u5316 SQL \u8a9e\u53e5\u662f\u63d0\u5347\u7cfb\u7d71\u6027\u80fd\u7684\u95dc\u9375\u3002Oracle \u6578\u64da\u5eab\u4f5c\u70ba\u4e00\u500b\u5ee3\u6cdb\u4f7f\u7528\u7684\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u5176 SQL \u8a9e\u53e5\u7684\u512a\u5316\u898f\u5247\u5c0d\u65bc\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u4f86\u8aaa\u81f3\u95dc\u91cd\u8981\u3002\u672c\u6587\u5c07\u63a2\u8a0e Oracle \u8a9e\u53e5\u7684\u512a\u5316\u898f\u5247\u4e2d\u7684\u5e7e\u500b\u91cd\u8981\u9805\u76ee\uff0c\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u5982\u4f55\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/p>\n<h2 id=\"1-%e4%bd%bf%e7%94%a8%e9%81%a9%e7%95%b6%e7%9a%84%e7%b4%a2%e5%bc%95-AIvJGqOpvp\">1. \u4f7f\u7528\u9069\u7576\u7684\u7d22\u5f15<\/h2>\n<p>\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u6709\u6548\u5de5\u5177\u3002Oracle \u652f\u6301\u591a\u7a2e\u7d22\u5f15\u985e\u578b\uff0c\u5305\u62ec B-tree \u7d22\u5f15\u3001\u4f4d\u5716\u7d22\u5f15\u548c\u53cd\u5411\u9375\u7d22\u5f15\u7b49\u3002\u9078\u64c7\u5408\u9069\u7684\u7d22\u5f15\u985e\u578b\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u901f\u5ea6\u3002<\/p>\n<ul>\n<li><strong>B-tree \u7d22\u5f15\uff1a<\/strong>\u9069\u5408\u65bc\u9ad8\u57fa\u6578\u7684\u5217\uff0c\u80fd\u5920\u5feb\u901f\u5b9a\u4f4d\u6578\u64da\u3002<\/li>\n<li><strong>\u4f4d\u5716\u7d22\u5f15\uff1a<\/strong>\u9069\u5408\u65bc\u4f4e\u57fa\u6578\u7684\u5217\uff0c\u7279\u5225\u662f\u5728\u6578\u64da\u5009\u5eab\u74b0\u5883\u4e2d\u3002<\/li>\n<li><strong>\u53cd\u5411\u9375\u7d22\u5f15\uff1a<\/strong>\u7528\u65bc\u9632\u6b62\u7d22\u5f15\u7684\u71b1\u9ede\u554f\u984c\uff0c\u7279\u5225\u662f\u5728\u63d2\u5165\u64cd\u4f5c\u983b\u7e41\u7684\u60c5\u6cc1\u4e0b\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u5c0d\u65bc\u4e00\u500b\u5305\u542b\u5927\u91cf\u7528\u6236\u6578\u64da\u7684\u8868\uff0c\u5982\u679c\u7d93\u5e38\u6839\u64da\u7528\u6236 ID \u67e5\u8a62\uff0c\u5247\u53ef\u4ee5\u70ba\u7528\u6236 ID \u5217\u5275\u5efa B-tree \u7d22\u5f15\uff1a<\/p>\n<pre><code>CREATE INDEX idx_user_id ON users(user_id);<\/code><\/pre>\n<h2 id=\"2-%e9%81%bf%e5%85%8d%e4%bd%bf%e7%94%a8-select-AIvJGqOpvp\">2. \u907f\u514d\u4f7f\u7528 SELECT *<\/h2>\n<p>\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528 SELECT * \u6703\u5c0e\u81f4\u4e0d\u5fc5\u8981\u7684\u6578\u64da\u50b3\u8f38\uff0c\u589e\u52a0 I\/O \u8ca0\u64d4\u3002\u61c9\u8a72\u660e\u78ba\u6307\u5b9a\u6240\u9700\u7684\u5217\uff0c\u9019\u6a23\u53ef\u4ee5\u6e1b\u5c11\u6578\u64da\u7684\u8b80\u53d6\u91cf\uff0c\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/p>\n<p>\u4f8b\u5982\uff0c\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT * FROM users WHERE user_id = 1;<\/code><\/pre>\n<p>\u53ef\u4ee5\u6539\u5beb\u70ba\uff1a<\/p>\n<pre><code>SELECT user_name, email FROM users WHERE user_id = 1;<\/code><\/pre>\n<h2 id=\"3-%e4%bd%bf%e7%94%a8-where-%e5%ad%90%e5%8f%a5%e9%81%8e%e6%bf%be%e6%95%b8%e6%93%9a-AIvJGqOpvp\">3. \u4f7f\u7528 WHERE \u5b50\u53e5\u904e\u6ffe\u6578\u64da<\/h2>\n<p>\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528 WHERE \u5b50\u53e5\u53ef\u4ee5\u6709\u6548\u5730\u904e\u6ffe\u4e0d\u5fc5\u8981\u7684\u6578\u64da\uff0c\u6e1b\u5c11\u67e5\u8a62\u7684\u7d50\u679c\u96c6\u5927\u5c0f\u3002\u9019\u4e0d\u50c5\u63d0\u9ad8\u4e86\u67e5\u8a62\u901f\u5ea6\uff0c\u9084\u6e1b\u5c11\u4e86\u5167\u5b58\u7684\u4f7f\u7528\u3002<\/p>\n<p>\u4f8b\u5982\uff0c\u4ee5\u4e0b\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT * FROM orders;<\/code><\/pre>\n<p>\u53ef\u4ee5\u6539\u5beb\u70ba\uff1a<\/p>\n<pre><code>SELECT * FROM orders WHERE order_date &gt; '2023-01-01';<\/code><\/pre>\n<h2 id=\"4-%e4%bd%bf%e7%94%a8-join-%e8%80%8c%e9%9d%9e%e5%ad%90%e6%9f%a5%e8%a9%a2-AIvJGqOpvp\">4. \u4f7f\u7528 JOIN \u800c\u975e\u5b50\u67e5\u8a62<\/h2>\n<p>\u5728\u8a31\u591a\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528 JOIN \u4f86\u9023\u63a5\u591a\u500b\u8868\u6bd4\u4f7f\u7528\u5b50\u67e5\u8a62\u66f4\u9ad8\u6548\u3002JOIN \u53ef\u4ee5\u5728\u55ae\u500b\u67e5\u8a62\u4e2d\u7372\u53d6\u6240\u9700\u7684\u6578\u64da\uff0c\u6e1b\u5c11\u4e86\u591a\u6b21\u67e5\u8a62\u7684\u958b\u92b7\u3002<\/p>\n<p>\u4f8b\u5982\uff0c\u4ee5\u4e0b\u5b50\u67e5\u8a62\uff1a<\/p>\n<pre><code>SELECT user_id FROM users WHERE user_id IN (SELECT user_id FROM orders);<\/code><\/pre>\n<p>\u53ef\u4ee5\u6539\u5beb\u70ba\uff1a<\/p>\n<pre><code>SELECT DISTINCT u.user_id FROM users u JOIN orders o ON u.user_id = o.user_id;<\/code><\/pre>\n<h2 id=\"5-%e4%bd%bf%e7%94%a8%e5%90%88%e9%81%a9%e7%9a%84%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-AIvJGqOpvp\">5. \u4f7f\u7528\u5408\u9069\u7684\u6578\u64da\u985e\u578b<\/h2>\n<p>\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b\u4e0d\u50c5\u53ef\u4ee5\u7bc0\u7701\u5b58\u5132\u7a7a\u9593\uff0c\u9084\u80fd\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u3002\u61c9\u6839\u64da\u5be6\u969b\u9700\u6c42\u9078\u64c7\u6700\u5408\u9069\u7684\u6578\u64da\u985e\u578b\uff0c\u907f\u514d\u4f7f\u7528\u904e\u5927\u7684\u6578\u64da\u985e\u578b\u3002<\/p>\n<p>\u4f8b\u5982\uff0c\u5c0d\u65bc\u4e00\u500b\u53ea\u9700\u8981\u5b58\u5132 0 \u5230 255 \u7684\u6574\u6578\uff0c\u53ef\u4ee5\u4f7f\u7528 TINYINT \u800c\u4e0d\u662f INT\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-AIvJGqOpvp\">\u7e3d\u7d50<\/h2>\n<p>\u512a\u5316 Oracle \u8a9e\u53e5\u7684\u904e\u7a0b\u4e2d\uff0c\u9078\u64c7\u5408\u9069\u7684\u7d22\u5f15\u3001\u907f\u514d\u4f7f\u7528 SELECT *\u3001\u4f7f\u7528 WHERE \u5b50\u53e5\u904e\u6ffe\u6578\u64da\u3001\u4f7f\u7528 JOIN \u800c\u975e\u5b50\u67e5\u8a62\u4ee5\u53ca\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u985e\u578b\u90fd\u662f\u91cd\u8981\u7684\u898f\u5247\u3002\u9019\u4e9b\u512a\u5316\u6280\u5de7\u4e0d\u50c5\u80fd\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u9084\u80fd\u63d0\u5347\u6574\u9ad4\u7cfb\u7d71\u7684\u6548\u7387\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u4f01\u696d\u4f86\u8aaa\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\uff0c\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u6578\u64da\u5eab\u904b\u884c\u5728\u6700\u4f73\u74b0\u5883\u4e2d\uff0c\u5f9e\u800c\u9054\u5230\u6700\u4f73\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22Oracle\u8a9e\u53e5\u512a\u5316\u898f\u5247\uff0c\u4e86\u89e3\u5982\u4f55\u63d0\u5347\u67e5\u8a62\u6548\u80fd\uff0c\u512a\u5316\u57f7\u884c\u8a08\u5283\uff0c\u4e26\u6539\u5584\u6578\u64da\u5eab\u6027\u80fd\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-94642","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/94642","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=94642"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/94642\/revisions"}],"predecessor-version":[{"id":94643,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/94642\/revisions\/94643"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=94642"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=94642"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=94642"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}