{"id":217830,"date":"2023-12-23T00:58:35","date_gmt":"2023-12-22T16:58:35","guid":{"rendered":"https:\/\/www.idc.net\/help\/217830\/"},"modified":"2023-12-23T00:58:35","modified_gmt":"2023-12-22T16:58:35","slug":"mysql%e4%bd%bf%e7%94%a8%e6%89%8b%e5%86%8c%ef%bc%9a%e4%bd%bf%e7%94%a8self-join%e6%9d%a5%e8%87%aa%e8%bf%9e%e6%8e%a5%e4%b8%80%e4%b8%aa%e8%a1%a8%ef%bc%8c%e5%b0%b1%e5%83%8f%e8%a1%a8%e6%98%af%e4%b8%a4","status":"publish","type":"post","link":"https:\/\/idc.net\/help\/217830\/","title":{"rendered":"MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528SELF JOIN\u6765\u81ea\u8fde\u63a5\u4e00\u4e2a\u8868\uff0c\u5c31\u50cf\u8868\u662f\u4e24\u4e2a\u8868\u4e00\u6837"},"content":{"rendered":"<p><title id=\"mysql%e4%bd%bf%e7%94%a8%e6%89%8b%e5%86%8c%ef%bc%9a%e4%bd%bf%e7%94%a8self-join%e6%9d%a5%e8%87%aa%e8%bf%9e%e6%8e%a5%e4%b8%80%e4%b8%aa%e8%a1%a8%ef%bc%8c%e5%b0%b1%e5%83%8f%e8%a1%a8%e6%98%af%e4%b8%a4-McnKGzTAjd\">MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528SELF JOIN\u6765\u81ea\u8fde\u63a5\u4e00\u4e2a\u8868\uff0c\u5c31\u50cf\u8868\u662f\u4e24\u4e2a\u8868\u4e00\u6837<\/title><\/p>\n<h1 id=\"mysql%e4%bd%bf%e7%94%a8%e6%89%8b%e5%86%8c%ef%bc%9a%e4%bd%bf%e7%94%a8self-join%e6%9d%a5%e8%87%aa%e8%bf%9e%e6%8e%a5%e4%b8%80%e4%b8%aa%e8%a1%a8%ef%bc%8c%e5%b0%b1%e5%83%8f%e8%a1%a8%e6%98%af%e4%b8%a4-McnKGzTAjd\">MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528SELF JOIN\u6765\u81ea\u8fde\u63a5\u4e00\u4e2a\u8868\uff0c\u5c31\u50cf\u8868\u662f\u4e24\u4e2a\u8868\u4e00\u6837<\/h1>\n<p>\u5728MySQL\u4e2d\uff0cSELF 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JOIN\u662f\u4e00\u79cd\u5c06\u8868\u81ea\u8eab\u8fde\u63a5\u8d77\u6765\u7684\u64cd\u4f5c\u3002\u5b83\u4f7f\u7528\u76f8\u540c\u7684\u8868\u540d\u6765\u5f15\u7528\u4e24\u4e2a\u4e0d\u540c\u7684\u5b9e\u4f8b\uff0c\u7136\u540e\u901a\u8fc7\u6307\u5b9a\u4e0d\u540c\u7684\u522b\u540d\u6765\u533a\u5206\u5b83\u4eec\u3002\u8fd9\u6837\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u5728\u540c\u4e00\u4e2a\u8868\u4e2d\u521b\u5efa\u4e00\u4e2a\u865a\u62df\u7684\u526f\u672c\uff0c\u5e76\u5c06\u5176\u89c6\u4e3a\u4e24\u4e2a\u4e0d\u540c\u7684\u8868\u3002<\/p>\n<h2 id=\"%e4%b8%ba%e4%bb%80%e4%b9%88%e4%bd%bf%e7%94%a8self-join%ef%bc%9f-McnKGzTAjd\">\u4e3a\u4ec0\u4e48\u4f7f\u7528SELF JOIN\uff1f<\/h2>\n<p>SELF JOIN\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u89e3\u51b3\u4e00\u4e9b\u590d\u6742\u7684\u67e5\u8be2\u95ee\u9898\uff0c\u7279\u522b\u662f\u5728\u5904\u7406\u5c42\u6b21\u7ed3\u6784\u6570\u636e\u65f6\u975e\u5e38\u6709\u7528\u3002\u4f8b\u5982\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528SELF JOIN\u6765\u67e5\u627e\u5458\u5de5\u7684\u4e0a\u7ea7\uff0c\u6216\u8005\u67e5\u627e\u4e00\u4e2a\u5458\u5de5\u7684\u6240\u6709\u4e0b\u5c5e\u3002<\/p>\n<h2 id=\"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8self-join%ef%bc%9f-McnKGzTAjd\">\u5982\u4f55\u4f7f\u7528SELF JOIN\uff1f<\/h2>\n<p>\u8981\u4f7f\u7528SELF JOIN\uff0c\u6211\u4eec\u9700\u8981\u4e3a\u8868\u521b\u5efa\u4e24\u4e2a\u4e0d\u540c\u7684\u522b\u540d\uff0c\u5e76\u4f7f\u7528\u8fd9\u4e9b\u522b\u540d\u6765\u5f15\u7528\u4e0d\u540c\u7684\u5b9e\u4f8b\u3002\u7136\u540e\uff0c\u6211\u4eec\u53ef\u4ee5\u5728JOIN\u5b50\u53e5\u4e2d\u4f7f\u7528\u8fd9\u4e9b\u522b\u540d\u6765\u6307\u5b9a\u8fde\u63a5\u6761\u4ef6\u3002<\/p>\n<p>\u4e0b\u9762\u662f\u4e00\u4e2a\u4f7f\u7528SELF JOIN\u67e5\u627e\u5458\u5de5\u7684\u4e0a\u7ea7\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>\nSELECT e1.employee_name, e2.employee_name AS supervisor_name\nFROM employees e1\nJOIN employees e2 ON e1.supervisor_id = e2.employee_id;\n<\/code><\/pre>\n<p>\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528\u4e86\u4e24\u4e2a\u522b\u540de1\u548ce2\u6765\u5f15\u7528\u540c\u4e00\u4e2aemployees\u8868\u7684\u4e0d\u540c\u5b9e\u4f8b\u3002\u7136\u540e\uff0c\u6211\u4eec\u5728JOIN\u5b50\u53e5\u4e2d\u6307\u5b9a\u4e86\u8fde\u63a5\u6761\u4ef6e1.supervisor_id = e2.employee_id\uff0c\u8fd9\u6837\u5c31\u53ef\u4ee5\u627e\u5230\u6bcf\u4e2a\u5458\u5de5\u7684\u4e0a\u7ea7\u3002<\/p>\n<h2 id=\"self-join%e7%9a%84%e5%ba%94%e7%94%a8%e5%9c%ba%e6%99%af-McnKGzTAjd\">SELF JOIN\u7684\u5e94\u7528\u573a\u666f<\/h2>\n<p>SELF JOIN\u5728\u5904\u7406\u5c42\u6b21\u7ed3\u6784\u6570\u636e\u65f6\u975e\u5e38\u6709\u7528\u3002\u4f8b\u5982\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528SELF JOIN\u6765\u67e5\u627e\u4e00\u4e2a\u5458\u5de5\u7684\u6240\u6709\u4e0b\u5c5e\u3002<\/p>\n<p>\u4e0b\u9762\u662f\u4e00\u4e2a\u4f7f\u7528SELF JOIN\u67e5\u627e\u5458\u5de5\u7684\u6240\u6709\u4e0b\u5c5e\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>\nSELECT e1.employee_name, e2.employee_name AS subordinate_name\nFROM employees e1\nJOIN employees e2 ON e1.employee_id = e2.supervisor_id;\n<\/code><\/pre>\n<p>\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528\u4e86\u4e24\u4e2a\u522b\u540de1\u548ce2\u6765\u5f15\u7528\u540c\u4e00\u4e2aemployees\u8868\u7684\u4e0d\u540c\u5b9e\u4f8b\u3002\u7136\u540e\uff0c\u6211\u4eec\u5728JOIN\u5b50\u53e5\u4e2d\u6307\u5b9a\u4e86\u8fde\u63a5\u6761\u4ef6e1.employee_id = e2.supervisor_id\uff0c\u8fd9\u6837\u5c31\u53ef\u4ee5\u627e\u5230\u6bcf\u4e2a\u5458\u5de5\u7684\u6240\u6709\u4e0b\u5c5e\u3002<\/p>\n<h2 id=\"%e6%80%bb%e7%bb%93-McnKGzTAjd\">\u603b\u7ed3<\/h2>\n<p>SELF JOIN\u662f\u4e00\u79cd\u7279\u6b8a\u7684JOIN\u64cd\u4f5c\uff0c\u5b83\u5141\u8bb8\u6211\u4eec\u5c06\u4e00\u4e2a\u8868\u81ea\u8eab\u8fde\u63a5\u8d77\u6765\uff0c\u5c31\u50cf\u5b83\u662f\u4e24\u4e2a\u4e0d\u540c\u7684\u8868\u4e00\u6837\u3002\u8fd9\u79cd\u8fde\u63a5\u65b9\u5f0f\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u89e3\u51b3\u4e00\u4e9b\u590d\u6742\u7684\u67e5\u8be2\u95ee\u9898\uff0c\u7279\u522b\u662f\u5728\u5904\u7406\u5c42\u6b21\u7ed3\u6784\u6570\u636e\u65f6\u975e\u5e38\u6709\u7528\u3002<\/p>\n<p>\u5982\u679c\u60a8\u60f3\u4e86\u89e3\u66f4\u591a\u5173\u4e8eMySQL\u7684\u4f7f\u7528\u624b\u518c\uff0c\u8bf7\u8bbf\u95ee\u6211\u4eec\u7684\u5b98\u65b9\u7f51\u7ad9\uff1a<a href=\"https:\/\/idc.net\">https:\/\/idc.net<\/a>\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528SELF JOIN\u6765\u81ea\u8fde\u63a5\u4e00\u4e2a\u8868\uff0c\u5c31\u50cf\u8868\u662f\u4e24\u4e2a\u8868\u4e00\u6837 MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528SELF [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[197851],"tags":[],"class_list":["post-217830","post","type-post","status-publish","format-standard","hentry","category-php"],"_links":{"self":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/217830","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/comments?post=217830"}],"version-history":[{"count":0,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/217830\/revisions"}],"wp:attachment":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/media?parent=217830"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/categories?post=217830"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/tags?post=217830"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}