{"id":139,"date":"2019-07-22T21:43:17","date_gmt":"2019-07-22T13:43:17","guid":{"rendered":"http:\/\/www.cgh0610.cn\/?p=139"},"modified":"2019-07-22T21:43:17","modified_gmt":"2019-07-22T13:43:17","slug":"mysql%e4%b8%adif%e5%87%bd%e6%95%b0%e4%bd%bf%e7%94%a8","status":"publish","type":"post","link":"https:\/\/www.cgh0610.cn\/?p=139","title":{"rendered":"Mysql\u4e2dIF()\u51fd\u6570\u4f7f\u7528"},"content":{"rendered":"<p>mysql\u4e2dif()\u51fd\u6570\u5177\u4f53\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code class=\"language-sql line-numbers\">IF(expr1,expr2,expr3)\n#\u5982\u679cexpr1\u7684\u503c\u4e3atrue\uff0c\u5219\u8fd4\u56deexpr2\u7684\u503c\u3002\n#\u5982\u679cexpr1\u7684\u503c\u4e3afalse\uff0c\u5219\u8fd4\u56deexpr3\u7684\u503c\u3002\n<\/code><\/pre>\n<p>\u5176\u7ecf\u5e38\u5224\u65ad\u67e5\u8be2\u51fa\u6765\u7684\u503c\uff0c\u793a\u4f8b\uff1b<\/p>\n<pre><code class=\"language-sql line-numbers\">mysql&gt; select name,if(sex=0,'\u5973','\u7537') as sex from student;\n+-------+-----+\n| name  | sex |\n+-------+-----+\n| name1 | \u5973  |\n| name2 | \u5973  |\n| name3 | \u7537  |\n| name4 | \u5973  |\n+-------+-----+\n<\/code><\/pre>\n<p>\u5176\u4e5f\u7ecf\u5e38\u7528\u5230\u5224\u65ad\u7684\u5173\u8054\u6761\u4ef6\u4e2d\uff0c\u5176\u793a\u4f8b\u5982\u4e0b\uff1a<\/p>\n<pre><code class=\"language-sql line-numbers\">SELECT  s.SCHOOL_CITY as schoolCity,\n        s.SCHOOL_COUNTY as schoolCounty,\n        count(DISTINCT `s`.`SCHOOL_ID`) as schoolNum,\n        sum(m.duration) as sumDuration,\n        sum(`m`.`VIEWERCOUNT`) as viewLiveSum,\n        sum(m.replayViewerCount)as reViewSum,\n        sum(m.praisecount) as sumpraise,\n        sum(`m`.`VIEWERCOUNT`+m.replayViewerCount) as viewSum\n         from ((tbl_hbb_mobile_live_statistics m join tbl_hbb_resource_visit_map v) join tbl_school_info s)\n    where`m`.`RESOURCEID`= `v`.`RESOURCEID` \n        and if((`v`.`rangeTYPE`= '2'),(`v`.`rangeID`= `s`.`SCHOOL_ID`),(`v`.`parentId`= `s`.`SCHOOL_ID`))\n<\/code><\/pre>\n<p>\u8f6c\u8f7d\u81f3\uff1a<a href=\"https:\/\/www.cnblogs.com\/zjdxr-up\/p\/8383609.html\">https:\/\/www.cnblogs.com\/zjdxr-up\/p\/8383609.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>mysql\u4e2dif()\u51fd\u6570\u5177\u4f53\u8bed\u6cd5\u5982\u4e0b\uff1a IF(expr1,expr2,expr3) #\u5982\u679cexpr1\u7684\u503c\u4e3atr &hellip; <a href=\"https:\/\/www.cgh0610.cn\/?p=139\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb<span class=\"screen-reader-text\">Mysql\u4e2dIF()\u51fd\u6570\u4f7f\u7528<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"aside","meta":[],"categories":[39,12],"tags":[59,28],"_links":{"self":[{"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=\/wp\/v2\/posts\/139"}],"collection":[{"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=139"}],"version-history":[{"count":1,"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=\/wp\/v2\/posts\/139\/revisions"}],"predecessor-version":[{"id":140,"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=\/wp\/v2\/posts\/139\/revisions\/140"}],"wp:attachment":[{"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cgh0610.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}