{"id":750,"date":"2020-08-02T18:37:35","date_gmt":"2020-08-02T10:37:35","guid":{"rendered":"http:\/\/www.gbase8.cn\/?p=750"},"modified":"2020-09-15T10:03:59","modified_gmt":"2020-09-15T02:03:59","slug":"gbase-8a%e6%95%b0%e6%8d%ae%e5%ba%93%e9%9b%86%e7%be%a4%e6%9f%a5%e8%af%a2%e6%8a%a5%e9%94%99-too-many-columns","status":"publish","type":"post","link":"https:\/\/www.gbase8.cn\/en\/750","title":{"rendered":"\u5357\u5927\u901a\u7528GBase 8a\u6570\u636e\u5e93\u96c6\u7fa4\u67e5\u8be2\u62a5\u9519 too many columns"},"content":{"rendered":"<p>GBase 8a\u6570\u636e\u5e93\u96c6\u7fa4\uff0c\u5355\u4e2a\u8868\u6700\u591a\u652f\u63012000\u4e2a\u5217\uff0c\u5305\u62ec\u4e34\u65f6\u8868\u3002\u5728\u8fdb\u884c\u591a\u8868join\u65f6\uff0c\u5982\u679cselect\u90e8\u5206\u7528\u5230\u7684\u5217\u592a\u591a\uff0c\u4e5f\u4f1a\u9020\u6210\u4e2d\u95f4\u8868\u7684\u5217\u6570\u8d85\u8fc7\u4e862000\u4e2a\u3002<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Directory Navigation<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6a2b2c940c664\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-6a2b2c940c664\"  aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.gbase8.cn\/en\/750\/#%E5%8E%9F%E5%9B%A0%EF%BC%9A\" >\u539f\u56e0\uff1a<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.gbase8.cn\/en\/750\/#%E8%A7%A3%E5%86%B3%EF%BC%9A\" >\u89e3\u51b3\uff1a<\/a><\/li><\/ul><\/nav><\/div>\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%8E%9F%E5%9B%A0%EF%BC%9A\"><\/span>\u539f\u56e0\uff1a<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>GBase\u5355\u4e2a\u8868\u6700\u591a2000\u4e2a\u5217\uff0c\u5305\u62ec<span class=\"has-inline-color has-luminous-vivid-orange-color\">\u4e34\u65f6\u8868<\/span>\u3002\u800c\u5ba2\u6237\u5728\u8fdb\u884c\u591a\u8868join\u65f6\uff0c\u4e2d\u95f4\u8868\u7684\u5217\u6570\u8d85\u8fc7\u4e862000\u4e2a\u3002<\/p>\n\n\n\n<p>\u5e38\u89c1SQL\u5982\u4e0b\uff1a<\/p>\n\n\n\n<p>select * from A join b join c ... <\/p>\n\n\n\n<p> \u67e5\u8be2\u7684\u8fd4\u56de\u5217\uff0c\u8d85\u8fc7\u4e862000\u4e2a\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E8%A7%A3%E5%86%B3%EF%BC%9A\"><\/span>\u89e3\u51b3\uff1a<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>\u51cf\u5c11join\u7ed3\u679c\u7684\u5217\u6570\u3002 <\/p>","protected":false},"excerpt":{"rendered":"<p>\u5357\u5927\u901a\u7528GBase 8a\u6570\u636e\u5e93\u96c6\u7fa4\uff0c\u5355\u4e2a\u8868\u6700\u591a\u652f\u63012000\u4e2a\u5217\uff0c\u5305\u62ec\u4e34\u65f6\u8868\u3002\u5728\u8fdb\u884c\u591a\u8868join\u65f6\uff0c\u5982\u679cselect\u90e8\u5206\u7528\u5230\u7684\u5217\u592a\u591a\uff0c\u4e5f\u4f1a\u9020\u6210\u4e2d\u95f4\u8868\u7684\u5217\u6570\u8d85\u8fc7\u4e862000\u4e2a\u3002<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[54],"tags":[],"class_list":["post-750","post","type-post","status-publish","format-standard","hentry","category-gbase8a"],"_links":{"self":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/750","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/comments?post=750"}],"version-history":[{"count":4,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/750\/revisions"}],"predecessor-version":[{"id":1309,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/750\/revisions\/1309"}],"wp:attachment":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/media?parent=750"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/categories?post=750"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/tags?post=750"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}