{"id":96082,"date":"2024-10-20T06:27:17","date_gmt":"2024-10-19T22:27:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/96082\/"},"modified":"2024-10-20T06:27:17","modified_gmt":"2024-10-19T22:27:17","slug":"oracle%e6%8f%90%e9%ab%98sql%e7%9a%84%e5%9f%b7%e8%a1%8c%e6%95%88%e7%8e%87%e7%9a%843%e7%a8%ae%e5%a5%bd%e7%94%a8%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/96082\/","title":{"rendered":"Oracle\u63d0\u9ad8SQL\u7684\u57f7\u884c\u6548\u7387\u76843\u7a2e\u597d\u7528\u65b9\u6cd5"},"content":{"rendered":"<h1 id=\"oracle%e6%8f%90%e9%ab%98sql%e7%9a%84%e5%9f%b7%e8%a1%8c%e6%95%88%e7%8e%87%e7%9a%843%e7%a8%ae%e5%a5%bd%e7%94%a8%e6%96%b9%e6%b3%95-rTxZioavok\">Oracle\u63d0\u9ad8SQL\u7684\u57f7\u884c\u6548\u7387\u76843\u7a2e\u597d\u7528\u65b9\u6cd5<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u6027\u80fd\u5c0d\u65bc\u4f01\u696d\u7684\u904b\u71df\u81f3\u95dc\u91cd\u8981\u3002Oracle\u6578\u64da\u5eab\u4f5c\u70ba\u4e00\u500b\u5f37\u5927\u7684\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u591a\u7a2e\u5de5\u5177\u548c\u6280\u8853\u4f86\u512a\u5316SQL\u67e5\u8a62\u7684\u57f7\u884c\u6548\u7387\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u4e09\u7a2e\u6709\u6548\u7684\u65b9\u6cd5\uff0c\u5e6b\u52a9\u7528\u6236\u63d0\u9ad8Oracle SQL\u7684\u57f7\u884c\u6548\u7387\u3002<\/p>\n<h2 id=\"1-%e4%bd%bf%e7%94%a8%e7%b4%a2%e5%bc%95%e4%be%86%e5%8a%a0%e9%80%9f%e6%9f%a5%e8%a9%a2-rTxZioavok\">1. \u4f7f\u7528\u7d22\u5f15\u4f86\u52a0\u901f\u67e5\u8a62<\/h2>\n<p>\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\u7684\u95dc\u9375\u5de5\u5177\u3002\u901a\u904e\u5728\u8868\u7684\u7279\u5b9a\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0cOracle\u53ef\u4ee5\u66f4\u5feb\u5730\u5b9a\u4f4d\u5230\u6240\u9700\u7684\u6578\u64da\uff0c\u800c\u4e0d\u5fc5\u6383\u63cf\u6574\u500b\u8868\u3002\u9019\u5c0d\u65bc\u5927\u578b\u6578\u64da\u96c6\u5c24\u70ba\u91cd\u8981\u3002<\/p>\n<ul>\n<li><strong>\u5275\u5efa\u7d22\u5f15\u7684\u57fa\u672c\u8a9e\u6cd5\uff1a<\/strong><\/li>\n<\/ul>\n<pre><code>CREATE INDEX index_name ON table_name (column_name);<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5047\u8a2d\u6709\u4e00\u500b\u540d\u70ba\u201cemployees\u201d\u7684\u8868\uff0c\u4e26\u4e14\u7d93\u5e38\u6839\u64da\u201clast_name\u201d\u5217\u9032\u884c\u67e5\u8a62\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u53e5\u5275\u5efa\u7d22\u5f15\uff1a<\/p>\n<pre><code>CREATE INDEX idx_last_name ON employees (last_name);<\/code><\/pre>\n<p>\u7136\u800c\uff0c\u904e\u591a\u7684\u7d22\u5f15\u6703\u5f71\u97ff\u6578\u64da\u63d2\u5165\u548c\u66f4\u65b0\u7684\u6027\u80fd\uff0c\u56e0\u6b64\u5728\u5275\u5efa\u7d22\u5f15\u6642\u9700\u8981\u8b39\u614e\u8003\u91cf\u3002<\/p>\n<h2 id=\"2-%e4%bd%bf%e7%94%a8%e6%9f%a5%e8%a9%a2%e5%84%aa%e5%8c%96%e5%99%a8-rTxZioavok\">2. \u4f7f\u7528\u67e5\u8a62\u512a\u5316\u5668<\/h2>\n<p>Oracle\u7684\u67e5\u8a62\u512a\u5316\u5668\u80fd\u5920\u81ea\u52d5\u9078\u64c7\u6700\u4f73\u7684\u57f7\u884c\u8a08\u5283\uff0c\u4ee5\u63d0\u9ad8\u67e5\u8a62\u7684\u6548\u7387\u3002\u7528\u6236\u53ef\u4ee5\u901a\u904e\u5206\u6790\u57f7\u884c\u8a08\u5283\u4f86\u4e86\u89e3\u67e5\u8a62\u7684\u6027\u80fd\u74f6\u9838\uff0c\u4e26\u9032\u884c\u76f8\u61c9\u7684\u8abf\u6574\u3002<\/p>\n<ul>\n<li><strong>\u67e5\u770b\u57f7\u884c\u8a08\u5283\u7684\u57fa\u672c\u8a9e\u6cd5\uff1a<\/strong><\/li>\n<\/ul>\n<pre><code>EXPLAIN PLAN FOR your_query;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5c0d\u65bc\u4e00\u500b\u67e5\u8a62\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u53e5\u4f86\u67e5\u770b\u5176\u57f7\u884c\u8a08\u5283\uff1a<\/p>\n<pre><code>EXPLAIN PLAN FOR SELECT * FROM employees WHERE last_name = 'Smith';<\/code><\/pre>\n<p>\u901a\u904e\u5206\u6790\u57f7\u884c\u8a08\u5283\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u8b58\u5225\u51fa\u54ea\u4e9b\u64cd\u4f5c\u662f\u6700\u8017\u6642\u7684\uff0c\u4e26\u6839\u64da\u9700\u8981\u9032\u884c\u512a\u5316\uff0c\u4f8b\u5982\u91cd\u5beb\u67e5\u8a62\u6216\u6dfb\u52a0\u7d22\u5f15\u3002<\/p>\n<h2 id=\"3-%e9%81%a9%e7%95%b6%e4%bd%bf%e7%94%a8%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b8%e5%92%8c%e5%ad%90%e6%9f%a5%e8%a9%a2-rTxZioavok\">3. \u9069\u7576\u4f7f\u7528\u805a\u5408\u51fd\u6578\u548c\u5b50\u67e5\u8a62<\/h2>\n<p>\u5728SQL\u67e5\u8a62\u4e2d\uff0c\u805a\u5408\u51fd\u6578\uff08\u5982SUM\u3001AVG\u3001COUNT\u7b49\uff09\u548c\u5b50\u67e5\u8a62\u7684\u4f7f\u7528\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u6578\u64da\u8655\u7406\u7684\u6548\u7387\u3002\u5408\u7406\u5730\u4f7f\u7528\u9019\u4e9b\u529f\u80fd\u53ef\u4ee5\u6e1b\u5c11\u6578\u64da\u7684\u50b3\u8f38\u91cf\u548c\u8a08\u7b97\u91cf\u3002<\/p>\n<ul>\n<li><strong>\u805a\u5408\u51fd\u6578\u7684\u793a\u4f8b\uff1a<\/strong><\/li>\n<\/ul>\n<pre><code>SELECT department_id, COUNT(*) FROM employees GROUP BY department_id;<\/code><\/pre>\n<p>\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u500b\u90e8\u9580\u7684\u54e1\u5de5\u6578\u91cf\uff0c\u901a\u904e\u4f7f\u7528\u805a\u5408\u51fd\u6578\uff0cOracle\u53ef\u4ee5\u5728\u6578\u64da\u5eab\u5c64\u9762\u9032\u884c\u8a08\u7b97\uff0c\u6e1b\u5c11\u4e86\u9700\u8981\u50b3\u8f38\u5230\u61c9\u7528\u5c64\u7684\u6578\u64da\u91cf\u3002<\/p>\n<p>\u6b64\u5916\uff0c\u4f7f\u7528\u5b50\u67e5\u8a62\u53ef\u4ee5\u5c07\u8907\u96dc\u7684\u67e5\u8a62\u5206\u89e3\u70ba\u66f4\u7c21\u55ae\u7684\u90e8\u5206\uff0c\u5f9e\u800c\u63d0\u9ad8\u53ef\u8b80\u6027\u548c\u7dad\u8b77\u6027\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT * FROM employees WHERE department_id IN (SELECT department_id FROM departments WHERE location_id = 1000);<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-rTxZioavok\">\u7e3d\u7d50<\/h2>\n<p>\u63d0\u9ad8Oracle SQL\u7684\u57f7\u884c\u6548\u7387\u662f\u6bcf\u4f4d\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u548c\u958b\u767c\u8005\u7684\u91cd\u8981\u4efb\u52d9\u3002\u901a\u904e\u4f7f\u7528\u7d22\u5f15\u3001\u67e5\u8a62\u512a\u5316\u5668\u4ee5\u53ca\u9069\u7576\u7684\u805a\u5408\u51fd\u6578\u548c\u5b50\u67e5\u8a62\uff0c\u60a8\u53ef\u4ee5\u986f\u8457\u63d0\u5347\u67e5\u8a62\u6027\u80fd\u3002\u9019\u4e9b\u65b9\u6cd5\u4e0d\u50c5\u80fd\u5920\u5e6b\u52a9\u60a8\u66f4\u5feb\u5730\u7372\u53d6\u6578\u64da\uff0c\u9084\u80fd\u63d0\u9ad8\u6574\u9ad4\u7cfb\u7d71\u7684\u97ff\u61c9\u901f\u5ea6\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u904b\u884c\u60a8\u7684Oracle\u6578\u64da\u5eab\uff0cServer.HK\u63d0\u4f9b\u4e86\u591a\u7a2e\u9078\u64c7\uff0c\u5e6b\u52a9\u60a8\u5be6\u73fe\u6700\u4f73\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22Oracle\u63d0\u9ad8SQL\u57f7\u884c\u6548\u7387\u7684\u4e09\u7a2e\u6709\u6548\u65b9\u6cd5\uff0c\u512a\u5316\u67e5\u8a62\u6027\u80fd\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u901f\u5ea6\uff0c\u52a9\u529b\u696d\u52d9\u589e\u9577\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-96082","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96082","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=96082"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96082\/revisions"}],"predecessor-version":[{"id":96083,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96082\/revisions\/96083"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=96082"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=96082"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=96082"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}