{"id":193,"date":"2023-10-01T07:47:53","date_gmt":"2023-09-30T23:47:53","guid":{"rendered":"http:\/\/blog.ohmmx.com\/?p=193"},"modified":"2023-10-01T07:47:53","modified_gmt":"2023-09-30T23:47:53","slug":"order-by-%e5%b0%86%e7%a9%ba%e5%80%bcnull%e6%8e%92%e5%88%b0%e6%9c%80%e5%90%8e","status":"publish","type":"post","link":"http:\/\/blog.ohmmx.com\/?p=193","title":{"rendered":"ORDER BY \u5c06\u7a7a\u503cNULL\u6392\u5230\u6700\u540e"},"content":{"rendered":"\n<p>\u5728 ORDER BY \u7684\u65f6\u5019\uff0c\u9ed8\u8ba4\u5c06NULL\u6392\u5728\u6700\u524d\u9762\uff0c\u6211\u4eec\u8981\u5c06\u4ed6\u4eec\u6392\u5230\u540e\u9762\u53bb\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>ORDER BY col IS NULL, col DESC<\/code><\/pre>\n\n\n\n<p>\u6216\u8005\u52a0\u4e00\u4e2a\u4e3a\u7a7a\u7684\u5224\u65ad\uff0c\u5c31\u80fd\u4e3b\u52a8\u63a7\u5236\u5f80\u524d\u6392\u8fd8\u662f\u5f80\u540e\u6392\u3002\uff08IFNULL\u53c2\u65701\u4e3a\u7a7a\u8fd4\u56de\u53c2\u65702\uff09<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>ORDER BY IFNULL(col, 0) DESC, col DESC<\/code><\/pre>\n\n\n\n<p>\u6216\u8005\uff08ISNULL\u53c2\u65701\u4e3a\u7a7a\u8fd4\u56de1\uff0c\u4e0d\u4e3a\u7a7a\u8fd4\u56de0\uff09<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>ORDER BY ISNULL(col) ASC, col DESC<\/code><\/pre>\n\n\n\n<p>\u6216\u8005\uff08IF\u53c2\u65701\u4e3a\u771f\u8fd4\u56de\u53c2\u65702\uff0c\u4e3a\u5047\u8fd4\u56de\u53c2\u65703\uff09<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>ORDER BY IF(ISNULL(col), 0, 1) DESC, col<\/code><\/pre>\n\n\n\n<p>\u6548\u7387\u6bd4\u8f83<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>IFNULL() > IS NULL > ISNULL()<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 ORDER BY \u7684\u65f6\u5019\uff0c\u9ed8\u8ba4\u5c06NULL\u6392\u5728\u6700\u524d\u9762\uff0c\u6211\u4eec\u8981\u5c06\u4ed6\u4eec\u6392\u5230\u540e\u9762\u53bb\u3002 &hellip; <a href=\"http:\/\/blog.ohmmx.com\/?p=193\">\u7ee7\u7eed\u9605\u8bfb <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[37,17],"tags":[9,8],"class_list":["post-193","post","type-post","status-publish","format-standard","hentry","category-sql","category-17","tag-mysql","tag-8"],"_links":{"self":[{"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=\/wp\/v2\/posts\/193","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=193"}],"version-history":[{"count":1,"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=\/wp\/v2\/posts\/193\/revisions"}],"predecessor-version":[{"id":194,"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=\/wp\/v2\/posts\/193\/revisions\/194"}],"wp:attachment":[{"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=193"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=193"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.ohmmx.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=193"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}