{"id":96316,"date":"2024-10-20T08:24:17","date_gmt":"2024-10-20T00:24:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/96316\/"},"modified":"2024-10-20T08:24:17","modified_gmt":"2024-10-20T00:24:17","slug":"oracle%e5%b7%a6%e9%80%a3%e6%8e%a5%e7%9a%84%e5%af%a6%e4%be%8b%e6%bc%94%e7%a4%ba","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/96316\/","title":{"rendered":"Oracle\u5de6\u9023\u63a5\u7684\u5be6\u4f8b\u6f14\u793a"},"content":{"rendered":"<h1 id=\"oracle%e5%b7%a6%e9%80%a3%e6%8e%a5%e7%9a%84%e5%af%a6%e4%be%8b%e6%bc%94%e7%a4%ba-vodZzYirQQ\">Oracle\u5de6\u9023\u63a5\u7684\u5be6\u4f8b\u6f14\u793a<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u5de6\u9023\u63a5\uff08LEFT JOIN\uff09\u662f\u4e00\u7a2e\u5e38\u7528\u7684\u67e5\u8a62\u65b9\u6cd5\uff0c\u80fd\u5920\u5f9e\u5169\u500b\u6216\u591a\u500b\u8868\u4e2d\u63d0\u53d6\u6578\u64da\u3002\u9019\u7a2e\u65b9\u6cd5\u7279\u5225\u9069\u5408\u65bc\u9700\u8981\u4fdd\u7559\u5de6\u5074\u8868\u4e2d\u6240\u6709\u8a18\u9304\u7684\u60c5\u6cc1\uff0c\u5373\u4f7f\u53f3\u5074\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u8a18\u9304\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eOracle\u6578\u64da\u5eab\u4e2d\u7684\u5de6\u9023\u63a5\uff0c\u4e26\u63d0\u4f9b\u5be6\u4f8b\u6f14\u793a\u4ee5\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u5176\u7528\u6cd5\u3002<\/p>\n<h2 id=\"%e5%b7%a6%e9%80%a3%e6%8e%a5%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-vodZzYirQQ\">\u5de6\u9023\u63a5\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u5de6\u9023\u63a5\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>SELECT \u5217\u540d1, \u5217\u540d2, ...\nFROM \u88681\nLEFT JOIN \u88682\nON \u88681.\u5217\u540d = \u88682.\u5217\u540d;<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c\u88681\u662f\u5de6\u5074\u8868\uff0c\u88682\u662f\u53f3\u5074\u8868\u3002\u67e5\u8a62\u5c07\u8fd4\u56de\u88681\u4e2d\u7684\u6240\u6709\u8a18\u9304\uff0c\u4e26\u4e14\u5982\u679c\u88682\u4e2d\u6709\u5339\u914d\u7684\u8a18\u9304\uff0c\u5247\u6703\u986f\u793a\u76f8\u61c9\u7684\u6578\u64da\uff1b\u5982\u679c\u6c92\u6709\u5339\u914d\u7684\u8a18\u9304\uff0c\u5247\u88682\u7684\u5217\u5c07\u986f\u793a\u70baNULL\u3002<\/p>\n<h2 id=\"%e5%af%a6%e4%be%8b%e6%bc%94%e7%a4%ba-vodZzYirQQ\">\u5be6\u4f8b\u6f14\u793a<\/h2>\n<p>\u70ba\u4e86\u66f4\u597d\u5730\u7406\u89e3\u5de6\u9023\u63a5\u7684\u7528\u6cd5\uff0c\u8b93\u6211\u5011\u8003\u616e\u4ee5\u4e0b\u5169\u500b\u8868\uff1a<\/p>\n<ul>\n<li><strong>\u54e1\u5de5\u8868\uff08employees\uff09<\/strong>\n<ul>\n<li>employee_id<\/li>\n<li>employee_name<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u90e8\u9580\u8868\uff08departments\uff09<\/strong>\n<ul>\n<li>department_id<\/li>\n<li>department_name<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>\u5047\u8a2d\u6211\u5011\u7684\u54e1\u5de5\u8868\u5305\u542b\u4ee5\u4e0b\u6578\u64da\uff1a<\/p>\n<pre><code>employee_id | employee_name\n-------------|--------------\n1            | \u5f35\u4e09\n2            | \u674e\u56db\n3            | \u738b\u4e94<\/code><\/pre>\n<p>\u800c\u90e8\u9580\u8868\u5247\u5305\u542b\u4ee5\u4e0b\u6578\u64da\uff1a<\/p>\n<pre><code>department_id | department_name\n---------------|----------------\n1              | \u4eba\u529b\u8cc7\u6e90\n2              | \u6280\u8853\u90e8<\/code><\/pre>\n<p>\u73fe\u5728\uff0c\u6211\u5011\u5e0c\u671b\u67e5\u8a62\u6240\u6709\u54e1\u5de5\u53ca\u5176\u6240\u5c6c\u90e8\u9580\u7684\u540d\u7a31\u3002\u5982\u679c\u67d0\u4f4d\u54e1\u5de5\u6c92\u6709\u6240\u5c6c\u90e8\u9580\uff0c\u6211\u5011\u4ecd\u7136\u5e0c\u671b\u986f\u793a\u8a72\u54e1\u5de5\u7684\u59d3\u540d\u3002\u9019\u6642\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528\u5de6\u9023\u63a5\u4f86\u5be6\u73fe\uff1a<\/p>\n<pre><code>SELECT e.employee_id, e.employee_name, d.department_name\nFROM employees e\nLEFT JOIN departments d ON e.employee_id = d.department_id;<\/code><\/pre>\n<p>\u57f7\u884c\u4e0a\u8ff0\u67e5\u8a62\u5f8c\uff0c\u7d50\u679c\u5c07\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<pre><code>employee_id | employee_name | department_name\n-------------|----------------|----------------\n1            | \u5f35\u4e09           | \u4eba\u529b\u8cc7\u6e90\n2            | \u674e\u56db           | \u6280\u8853\u90e8\n3            | \u738b\u4e94           | NULL<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u738b\u4e94\u6c92\u6709\u6240\u5c6c\u90e8\u9580\uff0c\u56e0\u6b64\u5728\u7d50\u679c\u4e2d\u986f\u793a\u70baNULL\u3002\u9019\u6b63\u662f\u5de6\u9023\u63a5\u7684\u7279\u9ede\uff1a\u5373\u4f7f\u53f3\u5074\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u8a18\u9304\uff0c\u5de6\u5074\u8868\u4e2d\u7684\u6240\u6709\u8a18\u9304\u4ecd\u7136\u6703\u88ab\u8fd4\u56de\u3002<\/p>\n<h2 id=\"%e5%b7%a6%e9%80%a3%e6%8e%a5%e7%9a%84%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-vodZzYirQQ\">\u5de6\u9023\u63a5\u7684\u61c9\u7528\u5834\u666f<\/h2>\n<p>\u5de6\u9023\u63a5\u5728\u8a31\u591a\u5834\u666f\u4e2d\u90fd\u975e\u5e38\u6709\u7528\uff0c\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li>\u5831\u544a\u751f\u6210\uff1a\u7576\u9700\u8981\u751f\u6210\u5305\u542b\u6240\u6709\u5ba2\u6236\u53ca\u5176\u8a02\u55ae\u7684\u5831\u544a\u6642\uff0c\u5373\u4f7f\u67d0\u4e9b\u5ba2\u6236\u6c92\u6709\u8a02\u55ae\uff0c\u4e5f\u9700\u8981\u986f\u793a\u4ed6\u5011\u7684\u8cc7\u6599\u3002<\/li>\n<li>\u6578\u64da\u6574\u5408\uff1a\u5728\u6578\u64da\u6574\u5408\u904e\u7a0b\u4e2d\uff0c\u5de6\u9023\u63a5\u53ef\u4ee5\u5e6b\u52a9\u5f9e\u591a\u500b\u4f86\u6e90\u63d0\u53d6\u6578\u64da\uff0c\u4e26\u4fdd\u7559\u4e3b\u8981\u4f86\u6e90\u7684\u6240\u6709\u8a18\u9304\u3002<\/li>\n<li>\u6578\u64da\u5206\u6790\uff1a\u5728\u9032\u884c\u6578\u64da\u5206\u6790\u6642\uff0c\u5de6\u9023\u63a5\u53ef\u4ee5\u5e6b\u52a9\u5206\u6790\u67d0\u4e9b\u7279\u5b9a\u689d\u4ef6\u4e0b\u7684\u6578\u64da\uff0c\u800c\u4e0d\u6703\u4e1f\u5931\u91cd\u8981\u7684\u4e0a\u4e0b\u6587\u4fe1\u606f\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-vodZzYirQQ\">\u7e3d\u7d50<\/h2>\n<p>\u5de6\u9023\u63a5\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u67e5\u8a62\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u5f9e\u591a\u500b\u8868\u4e2d\u63d0\u53d6\u6240\u9700\u7684\u6578\u64da\uff0c\u4e26\u4fdd\u7559\u5de6\u5074\u8868\u4e2d\u7684\u6240\u6709\u8a18\u9304\u3002\u901a\u904e\u672c\u6587\u7684\u5be6\u4f8b\u6f14\u793a\uff0c\u76f8\u4fe1\u8b80\u8005\u5c0dOracle\u4e2d\u7684\u5de6\u9023\u63a5\u6709\u4e86\u66f4\u6df1\u5165\u7684\u7406\u89e3\u3002\u5982\u679c\u60a8\u9700\u8981\u9032\u4e00\u6b65\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\u6216\u60f3\u8981\u4e86\u89e3\u66f4\u591a\u6709\u95dc<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u7684\u8cc7\u8a0a\uff0c\u8acb\u96a8\u6642\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22Oracle\u5de6\u9023\u63a5\u7684\u5be6\u4f8b\u6f14\u793a\uff0c\u5b78\u7fd2\u5982\u4f55\u6709\u6548\u5730\u67e5\u8a62\u6578\u64da\u4e26\u8655\u7406\u7f3a\u5931\u503c\uff0c\u63d0\u5347\u6578\u64da\u5206\u6790\u6280\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-96316","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96316","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=96316"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96316\/revisions"}],"predecessor-version":[{"id":96317,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96316\/revisions\/96317"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=96316"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=96316"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=96316"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}