{"id":2534,"date":"2016-01-18T13:19:55","date_gmt":"2016-01-18T05:19:55","guid":{"rendered":"http:\/\/www.menglanglang.cn\/?p=2534"},"modified":"2022-11-16T09:40:54","modified_gmt":"2022-11-16T01:40:54","slug":"mysql%e6%8c%89%e5%ad%97%e6%ae%b5%e5%88%86%e7%bb%84%e5%8f%96%e6%9c%80%e5%a4%a7%e5%80%bc%e8%ae%b0%e5%bd%95","status":"publish","type":"post","link":"http:\/\/www.menglanglang.cn\/?p=2534","title":{"rendered":"Mysql\u6309\u5b57\u6bb5\u5206\u7ec4\u53d6\u6700\u5927\u503c\u8bb0\u5f55"},"content":{"rendered":"<p>\u8981\u6c42\uff1a\u83b7\u5f97\u6309 table1_id \u5206\u7ec4\uff0c\u5e76\u4e14\u53d6\u5f97 table2 \u4e2d age \u6700\u5927\u7684\u8bb0\u5f55\u4fe1\u606f\u3002<\/p>\n<p>\u65b9\u6cd5\u4e00\uff1a<br \/>\nselect * from (select * from table2 order by age desc) as a group by a.table1_id<\/p>\n<p>\u65b9\u6cd5\u4e8c\uff1a<br \/>\nselect a.* from table2 as a where age = (select max(age) from table2 where a.table1_id=table1_id)<\/p>\n<p>\u65b9\u6cd5\u4e09\uff1a<br \/>\nselect a.* from table2 as a where not exists (select * from table2 where table1_id=a.table1_id and age&gt;a.age)<\/p>\n<p>\u65b9\u6cd5\u56db\uff1a<br \/>\nselect a.* from table2 as a where exists (select count(*) from table2 where table1_id=a.table1_id and age&gt;a.age having count(*)=0)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u8981\u6c42\uff1a\u83b7\u5f97\u6309 table1_id \u5206\u7ec4\uff0c\u5e76\u4e14\u53d6\u5f97 table2 \u4e2d age \u6700\u5927\u7684\u8bb0\u5f55\u4fe1\u606f\u3002 \u65b9\u6cd5\u4e00\uff1a sel [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[800],"tags":[186,651,652],"class_list":["post-2534","post","type-post","status-publish","format-standard","hentry","category-mysql","tag-mysql","tag-651","tag-652"],"_links":{"self":[{"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=\/wp\/v2\/posts\/2534","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2534"}],"version-history":[{"count":1,"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=\/wp\/v2\/posts\/2534\/revisions"}],"predecessor-version":[{"id":5258,"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=\/wp\/v2\/posts\/2534\/revisions\/5258"}],"wp:attachment":[{"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2534"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2534"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.menglanglang.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2534"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}