{"id":234,"date":"2012-04-10T14:27:10","date_gmt":"2012-04-10T06:27:10","guid":{"rendered":"http:\/\/www.vcoo.cc\/blog\/?p=234"},"modified":"2012-04-10T14:27:10","modified_gmt":"2012-04-10T06:27:10","slug":"sql-server-null","status":"publish","type":"post","link":"https:\/\/vcoo.cc\/blog\/234\/","title":{"rendered":"SQL Server \u67e5\u8be2\u8bed\u53e5\u5bf9NULL\u503c\u7684\u5224\u65ad\u95ee\u9898"},"content":{"rendered":"<p>\u5728SQL Server\u4e2d\u67e5\u8be2\u6570\u636e\u4e2d\u6709null\u503c\u7684\u8bb0\u5f55\u4f1a\u4ea7\u751f\u8ba9\u521d\u5b66\u8005\u90c1\u95f7\u7684\u73b0\u8c61\uff0c\u5fae\u9177\u4e5f\u662f\u5bf9\u4e8enull\u503c\u6709\u70b9\u4e0d\u592a\u660e\u767d\uff0c\u8fd9\u91cc\u8bb0\u5f55\u4e00\u4e0b\u3002@VCOO<\/p>\n<p>\u4e3e\u4f8b\u6765\u8bf4\u660e\uff0c\u6709\u4e00\u4e2a\u8868Student\u53ea\u6709\u4e00\u4e2a\u5b57\u6bb5\u201cName\u201d\uff0c\u91cc\u9762\u6709\u4e09\u6761\u8bb0\u5f55\uff1a<\/p>\n<blockquote><p>\nName<br \/>\n&#8212;&#8212;&#8212;-<br \/>\n\u5f20\u4e09<br \/>\nnull<br \/>\n\u674e\u56db<\/p><\/blockquote>\n<p>\u6211\u5c1d\u8bd5\u5199\u4e0b\u9762\u7684\u67e5\u8be2\u8bed\u53e5\uff1a<\/p>\n<blockquote><p>Select * From Student where Name&lt;&gt;&#8217;\u5f20\u4e09&#8217;<\/p><\/blockquote>\n<p>\u731c\u4f1a\u51fa\u73b0\u4ec0\u4e48\u7ed3\u679c\uff0c\u5f88\u9057\u61be\u7ed3\u679c\u662f\uff1a<\/p>\n<blockquote><p>Name<br \/>\n&#8212;&#8212;&#8212;-<br \/>\n\u674e\u56db<\/p><\/blockquote>\n<p>\u4e3a\u4ec0\u4e48\u53ea\u6709\u4e00\u6761\u8bb0\u5f55\uff0c\u8fd9\u5c31\u662fnull\u5f15\u8d77\u7684\u9ebb\u70e6\uff0c\u5176\u5b83\u6211\u4eec\u60f3\u5f97\u5230\u7684\u7ed3\u679c\u662f\uff1a<\/p>\n<blockquote><p>Name<br \/>\n&#8212;&#8212;&#8212;-<br \/>\nnull<br \/>\n\u674e\u56db<\/p><\/blockquote>\n<p><strong>\u89e3\u51b3\u65b9\u6cd5\uff1a<\/strong><\/p>\n<p>\u6b63\u786e\u7684\u5199\u6cd5\u53ef\u4ee5\u8fd9\u6837\uff1a<\/p>\n<blockquote><p>Select * From Student where isnull(Name,&#8221;)&lt;&gt;&#8217;\u5f20\u4e09&#8217;<\/p><\/blockquote>\n<p>\u53e6\u5916\u5728\u9047\u5230null\u65f6\u8981\u591a\u52a0\u6ce8\u610f\uff0c\u6bd4\u5982\u67e5\u627e\u8bb0\u5f55\u4e3anull\u7684\u8bb0\u5f55\u8981\u7528Name is null \u800c\u4e0d\u8981\u7528Name=null<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728SQL Server\u4e2d\u67e5\u8be2\u6570\u636e\u4e2d\u6709null\u503c\u7684\u8bb0\u5f55\u4f1a\u4ea7\u751f\u8ba9\u521d\u5b66\u8005\u90c1\u95f7\u7684\u73b0\u8c61\uff0c\u5fae\u9177\u4e5f\u662f\u5bf9\u4e8enull\u503c\u6709\u70b9\u4e0d\u592a\u660e\u767d\uff0c\u8fd9\u91cc\u8bb0\u5f55\u4e00\u4e0b\u3002@VCOO<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[44,46],"class_list":["post-234","post","type-post","status-publish","format-standard","hentry","category-sql-server","tag-sql","tag-46","cat-11-id"],"_links":{"self":[{"href":"https:\/\/vcoo.cc\/blog\/wp-json\/wp\/v2\/posts\/234","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vcoo.cc\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vcoo.cc\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vcoo.cc\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vcoo.cc\/blog\/wp-json\/wp\/v2\/comments?post=234"}],"version-history":[{"count":0,"href":"https:\/\/vcoo.cc\/blog\/wp-json\/wp\/v2\/posts\/234\/revisions"}],"wp:attachment":[{"href":"https:\/\/vcoo.cc\/blog\/wp-json\/wp\/v2\/media?parent=234"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vcoo.cc\/blog\/wp-json\/wp\/v2\/categories?post=234"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vcoo.cc\/blog\/wp-json\/wp\/v2\/tags?post=234"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}