{"id":1971,"date":"2011-09-07T23:25:26","date_gmt":"2011-09-07T15:25:26","guid":{"rendered":"http:\/\/jason695.why3s.tw\/wordpress\/?p=1971"},"modified":"2011-09-08T00:37:00","modified_gmt":"2011-09-07T16:37:00","slug":"%e3%80%8cis-null%e3%80%8d%e3%80%81%e3%80%8c-null%e3%80%8d%e7%9a%84%e5%b7%ae%e7%95%b0","status":"publish","type":"post","link":"https:\/\/jason695.why3s.tw\/wordpress\/2011\/09\/07\/%e3%80%8cis-null%e3%80%8d%e3%80%81%e3%80%8c-null%e3%80%8d%e7%9a%84%e5%b7%ae%e7%95%b0\/","title":{"rendered":"\u300cis null\u300d\u3001\u300c= null\u300d\u7684\u5dee\u7570"},"content":{"rendered":"<p>\u5df2\u7fd2\u6163\u6293\u51fanull\u7684\u8cc7\u6599\uff0c\u8981\u4e0bwhere \u67d0\u67d0\u6b04\u4f4d is null\u4e86\uff0c<br \/>\n\u4eca\u5929\u81e8\u6642\u88abUSER\u554f\u5230\u300cis null\u300d\u3001\u300c= null\u300d\u9019\u5169\u8005\u7684\u5dee\u7570\u5728\u54ea\uff1f<\/p>\n<p>\u4ee5\u4e0b\u622a\u53d6MSDN\u7684\u8aaa\u660e\uff1a<\/p>\n<p><a href=\"http:\/\/technet.microsoft.com\/zh-tw\/library\/ms188795.aspx\">http:\/\/technet.microsoft.com\/zh-tw\/library\/ms188795.aspx<\/a><\/p>\n<p style=\"padding-left: 30px;\">\u82e5\u8981\u5224\u65b7\u904b\u7b97\u5f0f\u662f\u5426\u70ba NULL\uff0c\u8acb\u5229\u7528 IS NULL \u6216 IS NOT NULL \u4f86\u53d6\u4ee3\u6bd4\u8f03\u904b\u7b97\u5b50 (\u5982 = \u6216 !=)\u3002\u7576\u5169\u500b\u5f15\u6578\u6216\u5176\u4e2d\u4e00\u500b\u5f15\u6578\u662f NULL \u6642\uff0c\u6bd4\u8f03\u904b\u7b97\u5b50\u6703\u50b3\u56de UNKNOWN\u3002<\/p>\n<p><a href=\"http:\/\/technet.microsoft.com\/zh-tw\/library\/ms191270.aspx\">http:\/\/technet.microsoft.com\/zh-tw\/library\/ms191270.aspx<\/a><\/p>\n<p style=\"padding-left: 30px;\">\u6bd4\u8f03 Null \u503c\u6642\u9700\u8981\u7279\u5225\u6ce8\u610f\u3002\u6bd4\u8f03\u7684\u884c\u70ba\u6703\u6839\u64da SET ANSI_NULLS \u9078\u9805\u7684\u8a2d\u5b9a\u800c\u6709\u6240\u4e0d\u540c\u3002<\/p>\n<p style=\"padding-left: 30px;\">\u7576 SET ANSI_NULLS \u662f ON \u6642\uff0c\u6bd4\u8f03\u4e00\u500b\u6216\u591a\u500b Null \u904b\u7b97\u5f0f\u4e0d\u6703\u7522\u751f TRUE \u6216 FALSE \u7684\u7d50\u679c\uff0c\u800c\u6703\u7522\u751f UNKNOWN\u3002\u9019\u662f\u56e0\u70ba\u672a\u77e5\u7684\u503c\u7121\u6cd5\u8207\u4efb\u4f55\u503c\u9032\u884c\u908f\u8f2f\u6bd4\u8f03\u3002\u5982\u679c\u904b\u7b97\u5f0f\u8207\u5e38\u503c NULL \u6bd4\u8f03\uff0c\u6216\u662f\u5169\u500b\u904b\u7b97\u5f0f\u4e92\u76f8\u6bd4\u8f03\u4f46\u5176\u4e2d\u6709\u4e00\u500b\u662f NULL \u503c\uff0c\u5c31\u6703\u767c\u751f\u6b64\u72c0\u6cc1\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5df2\u7fd2\u6163\u6293\u51fanull\u7684\u8cc7\u6599\uff0c\u8981\u4e0bwhere \u67d0\u67d0\u6b04\u4f4d is null\u4e86\uff0c \u4eca\u5929\u81e8\u6642\u88abUSER\u554f\u5230\u300cis null &hellip; <a href=\"https:\/\/jason695.why3s.tw\/wordpress\/2011\/09\/07\/%e3%80%8cis-null%e3%80%8d%e3%80%81%e3%80%8c-null%e3%80%8d%e7%9a%84%e5%b7%ae%e7%95%b0\/\" class=\"more-link\">\u95b1\u8b80\u5168\u6587 <span class=\"screen-reader-text\">\u300cis null\u300d\u3001\u300c= null\u300d\u7684\u5dee\u7570<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[47],"tags":[],"class_list":["post-1971","post","type-post","status-publish","format-standard","hentry","category-sql-server","no-featured-image"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/posts\/1971","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=1971"}],"version-history":[{"count":0,"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/posts\/1971\/revisions"}],"wp:attachment":[{"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/media?parent=1971"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/categories?post=1971"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jason695.why3s.tw\/wordpress\/wp-json\/wp\/v2\/tags?post=1971"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}