{"id":110,"date":"2006-09-06T06:30:53","date_gmt":"2006-09-06T06:30:53","guid":{"rendered":"http:\/\/search.jason695.idv.tw:81\/wordpress\/?p=110"},"modified":"2016-08-04T13:41:55","modified_gmt":"2016-08-04T05:41:55","slug":"%e7%ac%9b%e5%8d%a1%e5%85%92%e4%b9%98%e7%a9%8d","status":"publish","type":"post","link":"https:\/\/jason695.why3s.tw\/wordpress\/2006\/09\/06\/%e7%ac%9b%e5%8d%a1%e5%85%92%e4%b9%98%e7%a9%8d\/","title":{"rendered":"\u7b1b\u5361\u5152\u4e58\u7a4d"},"content":{"rendered":"<p>\u7b1b\u5361\u5152\u4e58\u7a4d\u662f\u4e00\u500b\u7d50\u679c\u96c6\uff0c\u5167\u542b\u67e5\u8a62\u4e2d\u6bcf\u500b\u8868\u683c\u6bcf\u4e00\u5217\u7684\u6240\u6709\u53ef\u80fd\u7d44<br \/>\n\u5408\u3002\u7b1b\u5361\u5152\u4e58\u7a4d\u5e7e\u4e4e\u90fd\u662f\u4e0d\u6b63\u78ba\u7684\u7d50\u679c\u3002<\/p>\n<p>\u5169\u500b\u8868\u683c\u5728\u7d50\u5408\u6642\uff0c\u4e0d\u6307\u5b9a\u4efb\u4f55\u689d\u4ef6\uff0c\u5982\uff1a<br \/>\nSELECT employee.realname, salary.amount FROM employee, salary<br \/>\nSELECT employee.realname, salary.amount FROM employee JOIN salary<br \/>\nSELECT employee.realname, salary.amount FROM employee CROSS JOIN salary<br \/>\n\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0cemployee \u539f\u6709 4 \u7b46\u8cc7\u6599\uff0c\u800c salary \u6709 5 \u7b46\u8cc7\u6599\uff0c\u5728 JOIN \u4e4b\u5f8c\uff0c<br \/>\n\u7d50\u679c\u5c07\u662f\u5169\u8005\u8cc7\u6599\u7b46\u6578\u7684\u4e58\u7a4d\uff1a20\u3002<br \/>\n\u5c31\u7b49\u65bc\u662f\u5c07\u5169\u500b\u8cc7\u6599\u8868\u4e2d\uff0c\u6240\u6709\u53ef\u80fd\u7684\u7d44\u5408\u5168\u90e8\u5217\u51fa\u4f86\u4e00\u6a23\uff0c<br \/>\n\u5176\u7d50\u679c\u5728\u5be6\u52d9\u4e0a\u4e0d\u898b\u5f97\u6709\u610f\u7fa9\u3002\u9019\u7a2e\u7d50\u5408\u53ef\u88ab\u8996\u70ba\u5169\u500b\u8cc7\u6599\u8868\u7684<br \/>\n\u300c\u7b1b\u5361\u5152\u4e58\u7a4d\uff08Cartesian product\uff09\u300d\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u7b1b\u5361\u5152\u4e58\u7a4d\u662f\u4e00\u500b\u7d50\u679c\u96c6\uff0c\u5167\u542b\u67e5\u8a62\u4e2d\u6bcf\u500b\u8868\u683c\u6bcf\u4e00\u5217\u7684\u6240\u6709\u53ef\u80fd\u7d44 \u5408\u3002\u7b1b\u5361\u5152\u4e58\u7a4d\u5e7e\u4e4e\u90fd\u662f\u4e0d\u6b63\u78ba\u7684\u7d50\u679c\u3002 \u5169\u500b\u8868\u683c\u5728 &hellip; <a href=\"https:\/\/jason695.why3s.tw\/wordpress\/2006\/09\/06\/%e7%ac%9b%e5%8d%a1%e5%85%92%e4%b9%98%e7%a9%8d\/\" class=\"more-link\">\u95b1\u8b80\u5168\u6587 <span class=\"screen-reader-text\">\u7b1b\u5361\u5152\u4e58\u7a4d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[29],"tags":[],"class_list":["post-110","post","type-post","status-publish","format-standard","hentry","category-29","no-featured-image"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/posts\/110","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/comments?post=110"}],"version-history":[{"count":0,"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/posts\/110\/revisions"}],"wp:attachment":[{"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/media?parent=110"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/categories?post=110"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/tags?post=110"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}