{"id":180104,"date":"2024-11-09T07:26:20","date_gmt":"2024-11-08T23:26:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/180104\/"},"modified":"2024-11-09T07:26:21","modified_gmt":"2024-11-08T23:26:21","slug":"%e4%b8%89%e5%a4%a7%e6%95%b8%e6%93%9a%e5%ba%ab%e8%81%af%e5%90%88%e6%9f%a5%e8%a9%a2%ef%bc%8c%e8%ae%93%e4%bd%a0%e7%9a%84%e6%95%b8%e6%93%9a%e6%9b%b4%e7%b2%be%e6%ba%96%ef%bc%81-%e4%b8%89%e5%80%8b%e6%95%b8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/180104\/","title":{"rendered":"\u4e09\u5927\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62\uff0c\u8b93\u4f60\u7684\u6578\u64da\u66f4\u7cbe\u6e96\uff01 (\u4e09\u500b\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62)"},"content":{"rendered":"<h1 id=\"%e4%b8%89%e5%a4%a7%e6%95%b8%e6%93%9a%e5%ba%ab%e8%81%af%e5%90%88%e6%9f%a5%e8%a9%a2%ef%bc%8c%e8%ae%93%e4%bd%a0%e7%9a%84%e6%95%b8%e6%93%9a%e6%9b%b4%e7%b2%be%e6%ba%96%ef%bc%81-NooDxiFfQn\">\u4e09\u5927\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62\uff0c\u8b93\u4f60\u7684\u6578\u64da\u66f4\u7cbe\u6e96\uff01<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u6642\u4ee3\uff0c\u4f01\u696d\u548c\u958b\u767c\u8005\u9762\u81e8\u8457\u5927\u91cf\u6578\u64da\u7684\u6311\u6230\u3002\u5982\u4f55\u6709\u6548\u5730\u5f9e\u591a\u500b\u6578\u64da\u5eab\u4e2d\u63d0\u53d6\u548c\u6574\u5408\u6578\u64da\uff0c\u6210\u70ba\u4e86\u63d0\u5347\u696d\u52d9\u6c7a\u7b56\u548c\u5206\u6790\u80fd\u529b\u7684\u95dc\u9375\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u4e09\u7a2e\u4e3b\u8981\u7684\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62\u6280\u8853\uff0c\u5e6b\u52a9\u4f60\u66f4\u7cbe\u6e96\u5730\u7372\u53d6\u6240\u9700\u6578\u64da\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e6%95%b8%e6%93%9a%e5%ba%ab%e8%81%af%e5%90%88%e6%9f%a5%e8%a9%a2%ef%bc%9f-NooDxiFfQn\">\u4ec0\u9ebc\u662f\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62\uff1f<\/h2>\n<p>\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62\u662f\u6307\u5f9e\u591a\u500b\u6578\u64da\u5eab\u4e2d\u540c\u6642\u6aa2\u7d22\u6578\u64da\u7684\u904e\u7a0b\u3002\u9019\u7a2e\u6280\u8853\u53ef\u4ee5\u5e6b\u52a9\u7528\u6236\u5728\u4e0d\u540c\u7684\u6578\u64da\u6e90\u4e4b\u9593\u5efa\u7acb\u95dc\u806f\uff0c\u5f9e\u800c\u7372\u5f97\u66f4\u5168\u9762\u7684\u6578\u64da\u8996\u5716\u3002\u806f\u5408\u67e5\u8a62\u901a\u5e38\u6d89\u53ca\u5230 SQL \u8a9e\u8a00\uff0c\u4e26\u4e14\u53ef\u4ee5\u901a\u904e\u4e0d\u540c\u7684\u65b9\u5f0f\u4f86\u5be6\u73fe\u3002<\/p>\n<h2 id=\"%e4%b8%89%e7%a8%ae%e4%b8%bb%e8%a6%81%e7%9a%84%e6%95%b8%e6%93%9a%e5%ba%ab%e8%81%af%e5%90%88%e6%9f%a5%e8%a9%a2%e6%8a%80%e8%a1%93-NooDxiFfQn\">\u4e09\u7a2e\u4e3b\u8981\u7684\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62\u6280\u8853<\/h2>\n<h3 id=\"1-inner-join-NooDxiFfQn\">1. INNER JOIN<\/h3>\n<p>INNER JOIN \u662f\u6700\u5e38\u898b\u7684\u806f\u5408\u67e5\u8a62\u65b9\u5f0f\u4e4b\u4e00\u3002\u5b83\u53ea\u8fd4\u56de\u5728\u5169\u500b\u6216\u591a\u500b\u8868\u4e2d\u90fd\u5b58\u5728\u7684\u8a18\u9304\u3002\u9019\u610f\u5473\u8457\u53ea\u6709\u7576\u689d\u4ef6\u6eff\u8db3\u6642\uff0c\u6578\u64da\u624d\u6703\u88ab\u9078\u4e2d\u3002<\/p>\n<pre><code>SELECT a.column1, b.column2\nFROM table_a a\nINNER JOIN table_b b ON a.common_field = b.common_field;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u53ea\u6709\u7576 <code>table_a<\/code> \u548c <code>table_b<\/code> \u4e2d\u7684 <code>common_field<\/code> \u5339\u914d\u6642\uff0c\u624d\u6703\u8fd4\u56de\u76f8\u61c9\u7684\u6578\u64da\u3002<\/p>\n<h3 id=\"2-left-join-NooDxiFfQn\">2. LEFT JOIN<\/h3>\n<p>LEFT JOIN \u6703\u8fd4\u56de\u5de6\u5074\u8868\u4e2d\u7684\u6240\u6709\u8a18\u9304\uff0c\u5373\u4f7f\u53f3\u5074\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u8a18\u9304\u3002\u9019\u5c0d\u65bc\u9700\u8981\u4fdd\u7559\u5de6\u5074\u8868\u6240\u6709\u6578\u64da\u7684\u60c5\u6cc1\u975e\u5e38\u6709\u7528\u3002<\/p>\n<pre><code>SELECT a.column1, b.column2\nFROM table_a a\nLEFT JOIN table_b b ON a.common_field = b.common_field;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u5373\u4f7f <code>table_b<\/code> \u4e2d\u6c92\u6709\u8207 <code>table_a<\/code> \u7684 <code>common_field<\/code> \u5339\u914d\u7684\u8a18\u9304\uff0c<code>table_a<\/code> \u7684\u6240\u6709\u8a18\u9304\u4ecd\u7136\u6703\u88ab\u8fd4\u56de\uff0c\u4e26\u4e14 <code>table_b<\/code> \u7684\u76f8\u61c9\u5b57\u6bb5\u5c07\u986f\u793a\u70ba NULL\u3002<\/p>\n<h3 id=\"3-union-NooDxiFfQn\">3. UNION<\/h3>\n<p>UNION \u7528\u65bc\u5c07\u5169\u500b\u6216\u591a\u500b SELECT \u67e5\u8a62\u7684\u7d50\u679c\u5408\u4f75\u70ba\u4e00\u500b\u7d50\u679c\u96c6\u3002\u9019\u8981\u6c42\u6240\u6709\u67e5\u8a62\u7684\u5217\u6578\u548c\u6578\u64da\u985e\u578b\u5fc5\u9808\u76f8\u540c\u3002<\/p>\n<pre><code>SELECT column1, column2 FROM table_a\nUNION\nSELECT column1, column2 FROM table_b;<\/code><\/pre>\n<p>\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u4f86\u81ea <code>table_a<\/code> \u548c <code>table_b<\/code> \u7684\u6240\u6709\u552f\u4e00\u8a18\u9304\u3002\u5982\u679c\u9700\u8981\u5305\u62ec\u91cd\u8907\u7684\u8a18\u9304\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>UNION ALL<\/code>\u3002<\/p>\n<h2 id=\"%e6%95%b8%e6%93%9a%e5%ba%ab%e8%81%af%e5%90%88%e6%9f%a5%e8%a9%a2%e7%9a%84%e6%87%89%e7%94%a8%e5%a0%b4%e6%99%af-NooDxiFfQn\">\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62\u7684\u61c9\u7528\u5834\u666f<\/h2>\n<ul>\n<li><strong>\u5831\u544a\u751f\u6210\uff1a<\/strong>\u901a\u904e\u806f\u5408\u67e5\u8a62\uff0c\u53ef\u4ee5\u5f9e\u4e0d\u540c\u7684\u6578\u64da\u5eab\u4e2d\u63d0\u53d6\u6578\u64da\uff0c\u751f\u6210\u7d9c\u5408\u5831\u544a\u3002<\/li>\n<li><strong>\u6578\u64da\u5206\u6790\uff1a<\/strong>\u5206\u6790\u4e0d\u540c\u4f86\u6e90\u7684\u6578\u64da\uff0c\u5e6b\u52a9\u4f01\u696d\u505a\u51fa\u66f4\u660e\u667a\u7684\u6c7a\u7b56\u3002<\/li>\n<li><strong>\u6578\u64da\u6574\u5408\uff1a<\/strong>\u5c07\u4f86\u81ea\u4e0d\u540c\u7cfb\u7d71\u7684\u6578\u64da\u6574\u5408\u5230\u4e00\u500b\u8996\u5716\u4e2d\uff0c\u4fbf\u65bc\u7ba1\u7406\u548c\u4f7f\u7528\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-NooDxiFfQn\">\u7d50\u8ad6<\/h2>\n<p>\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u5e6b\u52a9\u4f01\u696d\u548c\u958b\u767c\u8005\u66f4\u6709\u6548\u5730\u7ba1\u7406\u548c\u5206\u6790\u6578\u64da\u3002\u901a\u904e\u4f7f\u7528 INNER JOIN\u3001LEFT JOIN \u548c UNION \u7b49\u6280\u8853\uff0c\u60a8\u53ef\u4ee5\u5f9e\u591a\u500b\u6578\u64da\u5eab\u4e2d\u63d0\u53d6\u6240\u9700\u7684\u4fe1\u606f\uff0c\u5f9e\u800c\u63d0\u9ad8\u6578\u64da\u7684\u6e96\u78ba\u6027\u548c\u53ef\u7528\u6027\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u7ba1\u7406\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u4f86\u652f\u6301\u60a8\u7684\u6578\u64da\u5eab\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u4e91\u670d\u52a1\u5668<\/a> \u9084\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u670d\u52a1\u5668<\/a>\uff0c\u6211\u5011\u90fd\u80fd\u63d0\u4f9b\u7a69\u5b9a\u7684\u6027\u80fd\u548c\u9748\u6d3b\u7684\u914d\u7f6e\u9078\u64c7\uff0c\u52a9\u60a8\u5728\u6578\u64da\u7ba1\u7406\u4e0a\u66f4\u4e0a\u4e00\u5c64\u6a13\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e09\u5927\u6578\u64da\u5eab\u806f\u5408\u67e5\u8a62\uff0c\u63d0\u5347\u6578\u64da\u7cbe\u6e96\u5ea6\uff0c\u52a9\u4f60\u5feb\u901f\u7372\u53d6\u6240\u9700\u8cc7\u8a0a\uff0c\u512a\u5316\u6c7a\u7b56\u904e\u7a0b\uff0c\u5be6\u73fe\u6578\u64da\u50f9\u503c\u6700\u5927\u5316\uff01<\/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-180104","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/180104","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=180104"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/180104\/revisions"}],"predecessor-version":[{"id":180105,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/180104\/revisions\/180105"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=180104"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=180104"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=180104"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}