{"id":181558,"date":"2024-11-09T18:03:19","date_gmt":"2024-11-09T10:03:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/181558\/"},"modified":"2024-11-09T18:03:19","modified_gmt":"2024-11-09T10:03:19","slug":"%e6%b7%b1%e5%85%a5%e6%b7%ba%e5%87%basql%e4%b9%8b%e5%b7%a6%e9%80%a3%e6%8e%a5%e3%80%81%e5%8f%b3%e9%80%a3%e6%8e%a5%e5%92%8c%e5%85%a8%e9%80%a3%e6%8e%a5","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/181558\/","title":{"rendered":"\u6df1\u5165\u6dfa\u51faSQL\u4e4b\u5de6\u9023\u63a5\u3001\u53f3\u9023\u63a5\u548c\u5168\u9023\u63a5"},"content":{"rendered":"<h1 id=\"%e6%b7%b1%e5%85%a5%e6%b7%ba%e5%87%basql%e4%b9%8b%e5%b7%a6%e9%80%a3%e6%8e%a5%e3%80%81%e5%8f%b3%e9%80%a3%e6%8e%a5%e5%92%8c%e5%85%a8%e9%80%a3%e6%8e%a5-uuMfxskbZs\">\u6df1\u5165\u6dfa\u51faSQL\u4e4b\u5de6\u9023\u63a5\u3001\u53f3\u9023\u63a5\u548c\u5168\u9023\u63a5<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cSQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u4e00\u7a2e\u7528\u65bc\u67e5\u8a62\u548c\u64cd\u4f5c\u6578\u64da\u7684\u6a19\u6e96\u8a9e\u8a00\u3002\u7576\u6211\u5011\u9700\u8981\u5f9e\u591a\u500b\u8868\u4e2d\u63d0\u53d6\u6578\u64da\u6642\uff0c\u9023\u63a5\uff08JOIN\uff09\u64cd\u4f5c\u662f\u5fc5\u4e0d\u53ef\u5c11\u7684\u3002\u672c\u6587\u5c07\u6df1\u5165\u6dfa\u51fa\u5730\u4ecb\u7d39\u4e09\u7a2e\u5e38\u898b\u7684\u9023\u63a5\u985e\u578b\uff1a\u5de6\u9023\u63a5\uff08LEFT JOIN\uff09\u3001\u53f3\u9023\u63a5\uff08RIGHT JOIN\uff09\u548c\u5168\u9023\u63a5\uff08FULL JOIN\uff09\uff0c\u4e26\u901a\u904e\u793a\u4f8b\u4f86\u5e6b\u52a9\u7406\u89e3\u5b83\u5011\u7684\u7528\u6cd5\u3002<\/p>\n<h2 id=\"%e5%b7%a6%e9%80%a3%e6%8e%a5%ef%bc%88left-join%ef%bc%89-uuMfxskbZs\">\u5de6\u9023\u63a5\uff08LEFT JOIN\uff09<\/h2>\n<p>\u5de6\u9023\u63a5\u662f\u6307\u5f9e\u5de6\u5074\u8868\u4e2d\u9078\u53d6\u6240\u6709\u7684\u8a18\u9304\uff0c\u5373\u4f7f\u5728\u53f3\u5074\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u8a18\u9304\u3002\u9019\u610f\u5473\u8457\u5de6\u5074\u8868\u7684\u6240\u6709\u884c\u90fd\u6703\u51fa\u73fe\u5728\u7d50\u679c\u96c6\u4e2d\uff0c\u800c\u53f3\u5074\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u884c\u5247\u6703\u986f\u793a\u70baNULL\u3002<\/p>\n<h3 id=\"%e8%aa%9e%e6%b3%95-uuMfxskbZs\">\u8a9e\u6cd5<\/h3>\n<pre><code>SELECT \u5217\u540d\nFROM \u88681\nLEFT JOIN \u88682\nON \u88681.\u5217\u540d = \u88682.\u5217\u540d;<\/code><\/pre>\n<h3 id=\"%e7%a4%ba%e4%be%8b-uuMfxskbZs\">\u793a\u4f8b<\/h3>\n<p>\u5047\u8a2d\u6709\u5169\u500b\u8868\uff1a<strong>\u5b78\u751f<\/strong>\u548c<strong>\u6210\u7e3e<\/strong>\u3002<\/p>\n<ul>\n<li><strong>\u5b78\u751f<\/strong>\u8868\uff1a<\/li>\n<pre><code>\u5b78\u751fID | \u59d3\u540d\n1      | \u5f35\u4e09\n2      | \u674e\u56db\n3      | \u738b\u4e94<\/code><\/pre>\n<li><strong>\u6210\u7e3e<\/strong>\u8868\uff1a<\/li>\n<pre><code>\u5b78\u751fID | \u79d1\u76ee | \u6210\u7e3e\n1      | \u6578\u5b78 | 90\n1      | \u82f1\u6587 | 85\n2      | \u6578\u5b78 | 78<\/code><\/pre>\n<\/ul>\n<p>\u5982\u679c\u6211\u5011\u60f3\u8981\u67e5\u8a62\u6240\u6709\u5b78\u751f\u53ca\u5176\u6210\u7e3e\uff0c\u53ef\u4ee5\u4f7f\u7528\u5de6\u9023\u63a5\uff1a<\/p>\n<pre><code>SELECT \u5b78\u751f.\u59d3\u540d, \u6210\u7e3e.\u79d1\u76ee, \u6210\u7e3e.\u6210\u7e3e\nFROM \u5b78\u751f\nLEFT JOIN \u6210\u7e3e ON \u5b78\u751f.\u5b78\u751fID = \u6210\u7e3e.\u5b78\u751fID;<\/code><\/pre>\n<p>\u7d50\u679c\u5c07\u986f\u793a\u6240\u6709\u5b78\u751f\uff0c\u5373\u4f7f\u67d0\u4e9b\u5b78\u751f\u6c92\u6709\u6210\u7e3e\u8a18\u9304\uff1a<\/p>\n<pre><code>\u59d3\u540d | \u79d1\u76ee | \u6210\u7e3e\n\u5f35\u4e09 | \u6578\u5b78 | 90\n\u5f35\u4e09 | \u82f1\u6587 | 85\n\u674e\u56db | \u6578\u5b78 | 78\n\u738b\u4e94 | NULL | NULL<\/code><\/pre>\n<h2 id=\"%e5%8f%b3%e9%80%a3%e6%8e%a5%ef%bc%88right-join%ef%bc%89-uuMfxskbZs\">\u53f3\u9023\u63a5\uff08RIGHT JOIN\uff09<\/h2>\n<p>\u53f3\u9023\u63a5\u8207\u5de6\u9023\u63a5\u76f8\u53cd\uff0c\u5b83\u5f9e\u53f3\u5074\u8868\u4e2d\u9078\u53d6\u6240\u6709\u7684\u8a18\u9304\uff0c\u5373\u4f7f\u5728\u5de6\u5074\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u8a18\u9304\u3002\u9019\u610f\u5473\u8457\u53f3\u5074\u8868\u7684\u6240\u6709\u884c\u90fd\u6703\u51fa\u73fe\u5728\u7d50\u679c\u96c6\u4e2d\uff0c\u800c\u5de6\u5074\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u884c\u5247\u6703\u986f\u793a\u70baNULL\u3002<\/p>\n<h3 id=\"%e8%aa%9e%e6%b3%95-uuMfxskbZs\">\u8a9e\u6cd5<\/h3>\n<pre><code>SELECT \u5217\u540d\nFROM \u88681\nRIGHT JOIN \u88682\nON \u88681.\u5217\u540d = \u88682.\u5217\u540d;<\/code><\/pre>\n<h3 id=\"%e7%a4%ba%e4%be%8b-uuMfxskbZs\">\u793a\u4f8b<\/h3>\n<p>\u4f7f\u7528\u76f8\u540c\u7684<strong>\u5b78\u751f<\/strong>\u548c<strong>\u6210\u7e3e<\/strong>\u8868\uff0c\u5982\u679c\u6211\u5011\u60f3\u8981\u67e5\u8a62\u6240\u6709\u6210\u7e3e\u53ca\u5176\u5c0d\u61c9\u7684\u5b78\u751f\uff0c\u53ef\u4ee5\u4f7f\u7528\u53f3\u9023\u63a5\uff1a<\/p>\n<pre><code>SELECT \u5b78\u751f.\u59d3\u540d, \u6210\u7e3e.\u79d1\u76ee, \u6210\u7e3e.\u6210\u7e3e\nFROM \u5b78\u751f\nRIGHT JOIN \u6210\u7e3e ON \u5b78\u751f.\u5b78\u751fID = \u6210\u7e3e.\u5b78\u751fID;<\/code><\/pre>\n<p>\u7d50\u679c\u5c07\u986f\u793a\u6240\u6709\u6210\u7e3e\uff0c\u5373\u4f7f\u67d0\u4e9b\u6210\u7e3e\u6c92\u6709\u5c0d\u61c9\u7684\u5b78\u751f\u8a18\u9304\uff1a<\/p>\n<pre><code>\u59d3\u540d | \u79d1\u76ee | \u6210\u7e3e\n\u5f35\u4e09 | \u6578\u5b78 | 90\n\u5f35\u4e09 | \u82f1\u6587 | 85\n\u674e\u56db | \u6578\u5b78 | 78\nNULL | \u82f1\u6587 | NULL<\/code><\/pre>\n<h2 id=\"%e5%85%a8%e9%80%a3%e6%8e%a5%ef%bc%88full-join%ef%bc%89-uuMfxskbZs\">\u5168\u9023\u63a5\uff08FULL JOIN\uff09<\/h2>\n<p>\u5168\u9023\u63a5\u662f\u5de6\u9023\u63a5\u548c\u53f3\u9023\u63a5\u7684\u7d44\u5408\uff0c\u5f9e\u5169\u500b\u8868\u4e2d\u9078\u53d6\u6240\u6709\u7684\u8a18\u9304\u3002\u5982\u679c\u67d0\u4e00\u5074\u7684\u8868\u4e2d\u6c92\u6709\u5339\u914d\u7684\u8a18\u9304\uff0c\u5247\u986f\u793a\u70baNULL\u3002<\/p>\n<h3 id=\"%e8%aa%9e%e6%b3%95-uuMfxskbZs\">\u8a9e\u6cd5<\/h3>\n<pre><code>SELECT \u5217\u540d\nFROM \u88681\nFULL JOIN \u88682\nON \u88681.\u5217\u540d = \u88682.\u5217\u540d;<\/code><\/pre>\n<h3 id=\"%e7%a4%ba%e4%be%8b-uuMfxskbZs\">\u793a\u4f8b<\/h3>\n<p>\u5982\u679c\u6211\u5011\u60f3\u8981\u67e5\u8a62\u6240\u6709\u5b78\u751f\u548c\u6240\u6709\u6210\u7e3e\uff0c\u53ef\u4ee5\u4f7f\u7528\u5168\u9023\u63a5\uff1a<\/p>\n<pre><code>SELECT \u5b78\u751f.\u59d3\u540d, \u6210\u7e3e.\u79d1\u76ee, \u6210\u7e3e.\u6210\u7e3e\nFROM \u5b78\u751f\nFULL JOIN \u6210\u7e3e ON \u5b78\u751f.\u5b78\u751fID = \u6210\u7e3e.\u5b78\u751fID;<\/code><\/pre>\n<p>\u7d50\u679c\u5c07\u986f\u793a\u6240\u6709\u5b78\u751f\u548c\u6240\u6709\u6210\u7e3e\uff0c\u7121\u8ad6\u662f\u5426\u6709\u5339\u914d\uff1a<\/p>\n<pre><code>\u59d3\u540d | \u79d1\u76ee | \u6210\u7e3e\n\u5f35\u4e09 | \u6578\u5b78 | 90\n\u5f35\u4e09 | \u82f1\u6587 | 85\n\u674e\u56db | \u6578\u5b78 | 78\n\u738b\u4e94 | NULL | NULL\nNULL | \u82f1\u6587 | NULL<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-uuMfxskbZs\">\u7e3d\u7d50<\/h2>\n<p>\u5de6\u9023\u63a5\u3001\u53f3\u9023\u63a5\u548c\u5168\u9023\u63a5\u662fSQL\u4e2d\u975e\u5e38\u91cd\u8981\u7684\u64cd\u4f5c\uff0c\u80fd\u5920\u5e6b\u52a9\u6211\u5011\u5f9e\u591a\u500b\u8868\u4e2d\u63d0\u53d6\u6240\u9700\u7684\u6578\u64da\u3002\u4e86\u89e3\u9019\u4e9b\u9023\u63a5\u7684\u4f7f\u7528\u60c5\u5883\u548c\u8a9e\u6cd5\uff0c\u5c0d\u65bc\u6578\u64da\u5eab\u7684\u64cd\u4f5c\u548c\u7ba1\u7406\u81f3\u95dc\u91cd\u8981\u3002\u5982\u679c\u60a8\u9700\u8981\u9ad8\u6548\u7684\u6578\u64da\u8655\u7406\u548c\u5b58\u5132\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u6216<a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a>\u4f86\u652f\u6301\u60a8\u7684\u696d\u52d9\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22SQL\u4e2d\u7684\u5de6\u9023\u63a5\u3001\u53f3\u9023\u63a5\u548c\u5168\u9023\u63a5\uff0c\u6df1\u5165\u6dfa\u51fa\u5730\u89e3\u6790\u5176\u539f\u7406\u8207\u61c9\u7528\uff0c\u52a9\u4f60\u8f15\u9b06\u638c\u63e1\u6578\u64da\u67e5\u8a62\u6280\u5de7\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-181558","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/181558","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=181558"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/181558\/revisions"}],"predecessor-version":[{"id":181559,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/181558\/revisions\/181559"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=181558"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=181558"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=181558"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}