{"id":168511,"date":"2024-11-06T12:59:18","date_gmt":"2024-11-06T04:59:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168511\/"},"modified":"2024-11-06T12:59:19","modified_gmt":"2024-11-06T04:59:19","slug":"sql-%e4%b8%ad-union-%e6%8c%87%e4%bb%a4%e7%9a%84%e7%94%a8%e6%b3%95","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168511\/","title":{"rendered":"SQL \u4e2d UNION \u6307\u4ee4\u7684\u7528\u6cd5"},"content":{"rendered":"<h1 id=\"sql-%e4%b8%ad-union-%e6%8c%87%e4%bb%a4%e7%9a%84%e7%94%a8%e6%b3%95-mDcqpKLtCj\">SQL \u4e2d UNION \u6307\u4ee4\u7684\u7528\u6cd5<\/h1>\n<p>\u5728\u8cc7\u6599\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\u8cc7\u6599\u7684\u6a19\u6e96\u8a9e\u8a00\u3002\u7576\u6211\u5011\u9700\u8981\u5f9e\u591a\u500b\u8cc7\u6599\u8868\u4e2d\u7372\u53d6\u8cc7\u6599\u6642\uff0cUNION \u6307\u4ee4\u662f\u4e00\u500b\u975e\u5e38\u6709\u7528\u7684\u5de5\u5177\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e SQL \u4e2d UNION \u6307\u4ee4\u7684\u7528\u6cd5\u53ca\u5176\u61c9\u7528\u7bc4\u4f8b\u3002<\/p>\n<h2 id=\"union-%e6%8c%87%e4%bb%a4%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-mDcqpKLtCj\">UNION \u6307\u4ee4\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>UNION \u6307\u4ee4\u7528\u65bc\u5408\u4f75\u5169\u500b\u6216\u591a\u500b SELECT \u67e5\u8a62\u7684\u7d50\u679c\u96c6\u3002\u4f7f\u7528 UNION \u6642\uff0c\u6240\u6709\u7684 SELECT \u67e5\u8a62\u5fc5\u9808\u5177\u6709\u76f8\u540c\u7684\u5217\u6578\uff0c\u4e26\u4e14\u5c0d\u61c9\u7684\u5217\u5fc5\u9808\u5177\u6709\u76f8\u4f3c\u7684\u8cc7\u6599\u985e\u578b\u3002UNION \u6307\u4ee4\u6703\u81ea\u52d5\u53bb\u9664\u91cd\u8907\u7684\u8a18\u9304\uff0c\u82e5\u5e0c\u671b\u4fdd\u7559\u91cd\u8907\u7684\u8a18\u9304\uff0c\u53ef\u4ee5\u4f7f\u7528 UNION ALL \u6307\u4ee4\u3002<\/p>\n<h2 id=\"union-%e7%9a%84%e8%aa%9e%e6%b3%95-mDcqpKLtCj\">UNION \u7684\u8a9e\u6cd5<\/h2>\n<pre><code>SELECT column1, column2, ...\nFROM table1\nWHERE condition\nUNION\nSELECT column1, column2, ...\nFROM table2\nWHERE condition;\n<\/code><\/pre>\n<p>\u5728\u9019\u6bb5\u8a9e\u6cd5\u4e2d\uff0c\u7b2c\u4e00\u500b SELECT \u67e5\u8a62\u7684\u7d50\u679c\u5c07\u8207\u7b2c\u4e8c\u500b SELECT \u67e5\u8a62\u7684\u7d50\u679c\u5408\u4f75\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528 UNION \u7684\u4e00\u500b\u7c21\u55ae\u7bc4\u4f8b\uff1a<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b%ef%bc%9a%e4%bd%bf%e7%94%a8-union-%e5%90%88%e4%bd%b5%e5%85%a9%e5%80%8b%e6%9f%a5%e8%a9%a2-mDcqpKLtCj\">\u7bc4\u4f8b\uff1a\u4f7f\u7528 UNION \u5408\u4f75\u5169\u500b\u67e5\u8a62<\/h3>\n<pre><code>SELECT name, email FROM customers\nWHERE country = 'Hong Kong'\nUNION\nSELECT name, email FROM suppliers\nWHERE country = 'Hong Kong';\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c\u6211\u5011\u5f9e\u5169\u500b\u4e0d\u540c\u7684\u8cc7\u6599\u8868\uff08customers \u548c suppliers\uff09\u4e2d\u9078\u53d6\u4f86\u81ea\u9999\u6e2f\u7684\u5ba2\u6236\u548c\u4f9b\u61c9\u5546\u7684\u59d3\u540d\u548c\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u3002\u6700\u7d42\u7684\u7d50\u679c\u96c6\u5c07\u5305\u542b\u6240\u6709\u4f86\u81ea\u9019\u5169\u500b\u8cc7\u6599\u8868\u7684\u7368\u7279\u8a18\u9304\u3002<\/p>\n<h2 id=\"union-%e8%88%87-union-all-%e7%9a%84%e5%8d%80%e5%88%a5-mDcqpKLtCj\">UNION \u8207 UNION ALL \u7684\u5340\u5225<\/h2>\n<p>\u5982\u524d\u6240\u8ff0\uff0cUNION \u6703\u81ea\u52d5\u53bb\u9664\u91cd\u8907\u7684\u8a18\u9304\uff0c\u800c UNION ALL \u5247\u6703\u4fdd\u7559\u6240\u6709\u7684\u8a18\u9304\uff0c\u5305\u62ec\u91cd\u8907\u7684\u90e8\u5206\u3002\u9019\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\u53ef\u80fd\u6703\u5f71\u97ff\u67e5\u8a62\u7684\u6027\u80fd\uff0c\u56e0\u70ba UNION \u9700\u8981\u984d\u5916\u7684\u8655\u7406\u4f86\u53bb\u9664\u91cd\u8907\u9805\u3002<\/p>\n<h3 id=\"%e7%af%84%e4%be%8b%ef%bc%9a%e4%bd%bf%e7%94%a8-union-all-mDcqpKLtCj\">\u7bc4\u4f8b\uff1a\u4f7f\u7528 UNION ALL<\/h3>\n<pre><code>SELECT name, email FROM customers\nWHERE country = 'Hong Kong'\nUNION ALL\nSELECT name, email FROM suppliers\nWHERE country = 'Hong Kong';\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c\u4f7f\u7528 UNION ALL \u5c07\u8fd4\u56de\u6240\u6709\u4f86\u81ea customers \u548c suppliers \u7684\u8a18\u9304\uff0c\u5305\u62ec\u91cd\u8907\u7684\u59d3\u540d\u548c\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8-union-%e7%9a%84%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-mDcqpKLtCj\">\u4f7f\u7528 UNION \u7684\u6ce8\u610f\u4e8b\u9805<\/h2>\n<ul>\n<li><strong>\u5217\u6578\u548c\u8cc7\u6599\u985e\u578b\uff1a<\/strong>\u6240\u6709\u7684 SELECT \u67e5\u8a62\u5fc5\u9808\u8fd4\u56de\u76f8\u540c\u6578\u91cf\u7684\u5217\uff0c\u4e14\u5c0d\u61c9\u7684\u5217\u5fc5\u9808\u5177\u6709\u76f8\u4f3c\u7684\u8cc7\u6599\u985e\u578b\u3002<\/li>\n<li><strong>\u6392\u5e8f\uff1a<\/strong>\u5982\u679c\u9700\u8981\u5c0d\u6700\u7d42\u7d50\u679c\u96c6\u9032\u884c\u6392\u5e8f\uff0c\u53ef\u4ee5\u5728\u6700\u5f8c\u4e00\u500b SELECT \u67e5\u8a62\u5f8c\u4f7f\u7528 ORDER BY \u5b50\u53e5\u3002<\/li>\n<li><strong>\u6027\u80fd\u8003\u91cf\uff1a<\/strong>\u5728\u8655\u7406\u5927\u91cf\u8cc7\u6599\u6642\uff0c\u4f7f\u7528 UNION \u53ef\u80fd\u6703\u5f71\u97ff\u6027\u80fd\uff0c\u7279\u5225\u662f\u7576\u53bb\u9664\u91cd\u8907\u8a18\u9304\u6642\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-mDcqpKLtCj\">\u7d50\u8ad6<\/h2>\n<p>UNION \u6307\u4ee4\u5728 SQL \u4e2d\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u6709\u6548\u5730\u5408\u4f75\u4f86\u81ea\u4e0d\u540c\u8cc7\u6599\u8868\u7684\u67e5\u8a62\u7d50\u679c\u3002\u7121\u8ad6\u662f\u4f7f\u7528 UNION \u9084\u662f UNION ALL\uff0c\u4e86\u89e3\u5176\u7528\u6cd5\u548c\u7279\u6027\u5c0d\u65bc\u8cc7\u6599\u5eab\u7ba1\u7406\u548c\u67e5\u8a62\u512a\u5316\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u900f\u904e\u9069\u7576\u7684\u4f7f\u7528\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u66f4\u9748\u6d3b\u5730\u8655\u7406\u8cc7\u6599\uff0c\u63d0\u5347\u61c9\u7528\u7a0b\u5f0f\u7684\u6548\u80fd\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc\u8cc7\u6599\u5eab\u7ba1\u7406\u6216\u5176\u4ed6\u6280\u8853\u9700\u6c42\u6709\u8208\u8da3\uff0c\u6b61\u8fce\u4e86\u89e3\u6211\u5011\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2f VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0c\u63d0\u4f9b\u7a69\u5b9a\u4e14\u9ad8\u6548\u7684\u4f3a\u670d\u5668\u670d\u52d9\uff0c\u52a9\u60a8\u8f15\u9b06\u7ba1\u7406\u60a8\u7684\u61c9\u7528\u7a0b\u5f0f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3 SQL \u4e2d UNION \u6307\u4ee4\u7684\u7528\u6cd5\uff0c\u5982\u4f55\u5408\u5e76\u591a\u4e2a\u67e5\u8be2\u7ed3\u679c\u96c6\uff0c\u63d0\u5347\u6570\u636e\u5904\u7406\u6548\u7387\u4e0e\u7075\u6d3b\u6027\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-168511","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168511","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=168511"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168511\/revisions"}],"predecessor-version":[{"id":168512,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168511\/revisions\/168512"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168511"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168511"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168511"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}