{"id":173373,"date":"2024-11-07T17:29:23","date_gmt":"2024-11-07T09:29:23","guid":{"rendered":"https:\/\/server.hk\/cnblog\/173373\/"},"modified":"2024-11-07T17:29:24","modified_gmt":"2024-11-07T09:29:24","slug":"%e5%a6%82%e4%bd%95%e9%ab%98%e6%95%88%e5%9c%b0%e9%80%b2%e8%a1%8c%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e5%a4%9a%e8%a1%a8%e6%90%9c%e7%b4%a2%ef%bc%9f-%e6%95%b8%e6%93%9a%e5%ba%ab-%e5%a4%9a%e8%a1%a8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/173373\/","title":{"rendered":"\u5982\u4f55\u9ad8\u6548\u5730\u9032\u884c\u6578\u64da\u5eab\u4e2d\u591a\u8868\u641c\u7d22\uff1f (\u6578\u64da\u5eab \u591a\u8868\u641c\u7d22)"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e9%ab%98%e6%95%88%e5%9c%b0%e9%80%b2%e8%a1%8c%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e5%a4%9a%e8%a1%a8%e6%90%9c%e7%b4%a2%ef%bc%9f-YXIGWugMuV\">\u5982\u4f55\u9ad8\u6548\u5730\u9032\u884c\u6578\u64da\u5eab\u4e2d\u591a\u8868\u641c\u7d22\uff1f<\/h1>\n<p>\u5728\u73fe\u4ee3\u61c9\u7528\u7a0b\u5e8f\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u4f7f\u7528\u5df2\u7d93\u8b8a\u5f97\u7121\u8655\u4e0d\u5728\u3002\u96a8\u8457\u6578\u64da\u91cf\u7684\u589e\u9577\uff0c\u5982\u4f55\u9ad8\u6548\u5730\u9032\u884c\u591a\u8868\u641c\u7d22\u6210\u70ba\u4e86\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u9762\u81e8\u7684\u4e00\u5927\u6311\u6230\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u591a\u8868\u641c\u7d22\u7684\u57fa\u672c\u6982\u5ff5\u3001\u5e38\u898b\u7684\u67e5\u8a62\u65b9\u6cd5\u4ee5\u53ca\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u7684\u6280\u5de7\u3002<\/p>\n<h2 id=\"%e5%a4%9a%e8%a1%a8%e6%90%9c%e7%b4%a2%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-YXIGWugMuV\">\u591a\u8868\u641c\u7d22\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u591a\u8868\u641c\u7d22\u662f\u6307\u5728\u6578\u64da\u5eab\u4e2d\u540c\u6642\u67e5\u8a62\u591a\u500b\u8868\u7684\u6578\u64da\u3002\u9019\u901a\u5e38\u6d89\u53ca\u5230\u4f7f\u7528 SQL \u8a9e\u53e5\u4e2d\u7684 JOIN \u64cd\u4f5c\u3002JOIN \u64cd\u4f5c\u53ef\u4ee5\u5c07\u5169\u500b\u6216\u591a\u500b\u8868\u6839\u64da\u67d0\u4e9b\u689d\u4ef6\u9023\u63a5\u8d77\u4f86\uff0c\u5f9e\u800c\u7372\u53d6\u6240\u9700\u7684\u6578\u64da\u3002<\/p>\n<h3 id=\"%e5%b8%b8%e8%a6%8b%e7%9a%84-join-%e9%a1%9e%e5%9e%8b-YXIGWugMuV\">\u5e38\u898b\u7684 JOIN \u985e\u578b<\/h3>\n<ul>\n<li><strong>INNER JOIN<\/strong>: \u53ea\u8fd4\u56de\u5169\u500b\u8868\u4e2d\u5339\u914d\u7684\u884c\u3002<\/li>\n<li><strong>LEFT JOIN<\/strong>: \u8fd4\u56de\u5de6\u8868\u4e2d\u7684\u6240\u6709\u884c\uff0c\u5373\u4f7f\u53f3\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u884c\u3002<\/li>\n<li><strong>RIGHT JOIN<\/strong>: \u8fd4\u56de\u53f3\u8868\u4e2d\u7684\u6240\u6709\u884c\uff0c\u5373\u4f7f\u5de6\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u884c\u3002<\/li>\n<li><strong>FULL OUTER JOIN<\/strong>: \u8fd4\u56de\u5169\u500b\u8868\u4e2d\u7684\u6240\u6709\u884c\uff0c\u7121\u8ad6\u662f\u5426\u6709\u5339\u914d\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a4%9a%e8%a1%a8%e6%90%9c%e7%b4%a2%e7%9a%84%e6%9f%a5%e8%a9%a2%e7%a4%ba%e4%be%8b-YXIGWugMuV\">\u591a\u8868\u641c\u7d22\u7684\u67e5\u8a62\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528 INNER JOIN \u7684\u7c21\u55ae\u67e5\u8a62\u793a\u4f8b\uff0c\u5047\u8a2d\u6211\u5011\u6709\u5169\u500b\u8868\uff1a<code>users<\/code> \u548c <code>orders<\/code>\u3002<\/p>\n<pre><code>SELECT users.name, orders.amount\nFROM users\nINNER JOIN orders ON users.id = orders.user_id;<\/code><\/pre>\n<p>\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6240\u6709\u7528\u6236\u7684\u59d3\u540d\u53ca\u5176\u8a02\u55ae\u91d1\u984d\uff0c\u50c5\u9650\u65bc\u90a3\u4e9b\u6709\u8a02\u55ae\u7684\u7528\u6236\u3002<\/p>\n<h2 id=\"%e6%8f%90%e9%ab%98%e5%a4%9a%e8%a1%a8%e6%90%9c%e7%b4%a2%e6%95%88%e7%8e%87%e7%9a%84%e6%8a%80%e5%b7%a7-YXIGWugMuV\">\u63d0\u9ad8\u591a\u8868\u641c\u7d22\u6548\u7387\u7684\u6280\u5de7<\/h2>\n<p>\u5728\u9032\u884c\u591a\u8868\u641c\u7d22\u6642\uff0c\u6548\u7387\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u7684\u6280\u5de7\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8%e7%b4%a2%e5%bc%95-YXIGWugMuV\">1. \u4f7f\u7528\u7d22\u5f15<\/h3>\n<p>\u70ba\u4e86\u52a0\u5feb\u67e5\u8a62\u901f\u5ea6\uff0c\u61c9\u8a72\u5728\u7d93\u5e38\u7528\u4f5c JOIN \u689d\u4ef6\u7684\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\u3002\u7d22\u5f15\u53ef\u4ee5\u986f\u8457\u6e1b\u5c11\u67e5\u8a62\u6240\u9700\u7684\u6642\u9593\u3002<\/p>\n<h3 id=\"2-%e9%81%a9%e7%95%b6%e9%81%b8%e6%93%87-join-%e9%a1%9e%e5%9e%8b-YXIGWugMuV\">2. \u9069\u7576\u9078\u64c7 JOIN \u985e\u578b<\/h3>\n<p>\u6839\u64da\u5be6\u969b\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684 JOIN \u985e\u578b\u3002\u4f8b\u5982\uff0c\u5982\u679c\u53ea\u9700\u8981\u5339\u914d\u7684\u6578\u64da\uff0c\u4f7f\u7528 INNER JOIN \u6703\u6bd4 LEFT JOIN \u66f4\u9ad8\u6548\u3002<\/p>\n<h3 id=\"3-%e9%99%90%e5%88%b6%e8%bf%94%e5%9b%9e%e7%9a%84%e5%88%97-YXIGWugMuV\">3. \u9650\u5236\u8fd4\u56de\u7684\u5217<\/h3>\n<p>\u5728 SELECT \u8a9e\u53e5\u4e2d\u50c5\u9078\u64c7\u9700\u8981\u7684\u5217\uff0c\u800c\u4e0d\u662f\u4f7f\u7528 <code>SELECT *<\/code>\uff0c\u9019\u6a23\u53ef\u4ee5\u6e1b\u5c11\u6578\u64da\u50b3\u8f38\u7684\u91cf\u3002<\/p>\n<pre><code>SELECT users.name\nFROM users\nINNER JOIN orders ON users.id = orders.user_id;<\/code><\/pre>\n<h3 id=\"4-%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-YXIGWugMuV\">4. \u4f7f\u7528 WHERE \u5b50\u53e5\u904e\u6ffe\u6578\u64da<\/h3>\n<p>\u5728\u67e5\u8a62\u4e2d\u4f7f\u7528 WHERE \u5b50\u53e5\u4f86\u904e\u6ffe\u4e0d\u5fc5\u8981\u7684\u6578\u64da\uff0c\u53ef\u4ee5\u6e1b\u5c11\u67e5\u8a62\u7684\u8ca0\u64d4\u3002<\/p>\n<pre><code>SELECT users.name, orders.amount\nFROM users\nINNER JOIN orders ON users.id = orders.user_id\nWHERE orders.amount &gt; 100;<\/code><\/pre>\n<h3 id=\"5-%e5%88%86%e6%9e%90%e6%9f%a5%e8%a9%a2%e8%a8%88%e5%8a%83-YXIGWugMuV\">5. \u5206\u6790\u67e5\u8a62\u8a08\u5283<\/h3>\n<p>\u4f7f\u7528\u6578\u64da\u5eab\u63d0\u4f9b\u7684\u67e5\u8a62\u8a08\u5283\u5206\u6790\u5de5\u5177\uff0c\u6aa2\u67e5\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u627e\u51fa\u6027\u80fd\u74f6\u9838\u4e26\u9032\u884c\u512a\u5316\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-YXIGWugMuV\">\u7e3d\u7d50<\/h2>\n<p>\u9ad8\u6548\u7684\u591a\u8868\u641c\u7d22\u5c0d\u65bc\u6578\u64da\u5eab\u6027\u80fd\u81f3\u95dc\u91cd\u8981\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528 JOIN \u64cd\u4f5c\u3001\u5275\u5efa\u7d22\u5f15\u3001\u9078\u64c7\u5408\u9069\u7684\u67e5\u8a62\u985e\u578b\u4ee5\u53ca\u904e\u6ffe\u4e0d\u5fc5\u8981\u7684\u6578\u64da\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002\u5c0d\u65bc\u9700\u8981\u8655\u7406\u5927\u91cf\u6578\u64da\u7684\u61c9\u7528\u7a0b\u5e8f\uff0c\u9078\u64c7\u5408\u9069\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u4e00\u500b\u91cd\u8981\u8003\u91cf\uff0c\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u6578\u64da\u5eab\u7684\u7a69\u5b9a\u6027\u548c\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2\u5982\u4f55\u9ad8\u6548\u9032\u884c\u6578\u64da\u5eab\u4e2d\u7684\u591a\u8868\u641c\u7d22\uff0c\u63d0\u5347\u67e5\u8a62\u6027\u80fd\uff0c\u512a\u5316\u6578\u64da\u6aa2\u7d22\uff0c\u5be6\u73fe\u5feb\u901f\u6e96\u78ba\u7684\u6578\u64da\u5206\u6790\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-173373","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/173373","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=173373"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/173373\/revisions"}],"predecessor-version":[{"id":173374,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/173373\/revisions\/173374"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=173373"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=173373"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=173373"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}