{"id":505,"date":"2021-05-11T00:00:18","date_gmt":"2021-05-11T00:00:18","guid":{"rendered":"http:\/\/emacslisp.com\/?p=505"},"modified":"2021-05-11T00:00:18","modified_gmt":"2021-05-11T00:00:18","slug":"influxdb-influxdb-query-for-ifelse-case","status":"publish","type":"post","link":"http:\/\/emacslisp.com\/?p=505","title":{"rendered":"influxdb &#8211; influxdb query for if\/else case"},"content":{"rendered":"<p>influxdb didn&#8217;t support if\/else in select statement.<\/p>\n<p>mysql could support if\/else\/case statement, for example.<\/p>\n<pre lang=\"sql\" line=\"1\">\r\n   select\r\n      CASE <field>\r\n         when 1 then 100\r\n      ELSE\r\n         0\r\n   from table\r\n   where [condition]\r\n<\/pre>\n<p>However, influxdb didn&#8217;t support if\/else in select statement.<br \/>\nwe have to use a function map for if\/else<\/p>\n<p>for example,<\/p>\n<p>input set is (1, 2, 3, 4, 5, 6, 7)<br \/>\noutput set is (100, 0, 0, 0, 0, 0, 0)<\/p>\n<p>we design a function f(x) = 100*FLOOR(1\/x)<\/p>\n<p>so f(1) = 100, f(2) = 0, &#8230; , f(7) = 0;<\/p>\n<p>it could match whole input set and output set<\/p>\n<pre lang=\"sql\" line=\"1\">\r\nselect 100*FLOOR(1\/field) from 'measurement' where <condition>\r\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>influxdb didn&#8217;t support if\/else in select statement. mysql could support if\/else\/case statement, for example. select CASE when 1 then 100 ELSE 0 from table where [condition] However, influxdb didn&#8217;t support if\/else in select statement. we have to use a function map for if\/else for example, input set is (1, 2, 3, 4, 5, 6, 7) [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28],"tags":[],"class_list":["post-505","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"http:\/\/emacslisp.com\/index.php?rest_route=\/wp\/v2\/posts\/505","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/emacslisp.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/emacslisp.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/emacslisp.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/emacslisp.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=505"}],"version-history":[{"count":1,"href":"http:\/\/emacslisp.com\/index.php?rest_route=\/wp\/v2\/posts\/505\/revisions"}],"predecessor-version":[{"id":506,"href":"http:\/\/emacslisp.com\/index.php?rest_route=\/wp\/v2\/posts\/505\/revisions\/506"}],"wp:attachment":[{"href":"http:\/\/emacslisp.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=505"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/emacslisp.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=505"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/emacslisp.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=505"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}