<\/span><\/h3>\n\n\n\n\u5982\u4e0b\u662f\u5148\u62ff\u5230\u5176\u4ed6\u5217\u5206\u7ec4\u540e\uff0c\u6700\u5927\u7684\u7f16\u53f7 max(id)\uff0c\u7528min(id)\u4e5f\u662f\u53ef\u4ee5\u7684\u3002\u7136\u540e\u5c06\u4e0d\u5c5e\u4e8e\u8fd9\u4e2a\u96c6\u5408\u7684\u6570\u636e\u90fd\u5220\u6389\u3002<\/p>\n\n\n\n
gbase> delete from exam_2 where id not in (select max(id) from exam_2 group by student_id,name,class_id,classname,score); Query OK, 1 row affected (Elapsed: 00:00:00.15)\n\ngbase> select * from exam_2;\n+------+------------+--------+----------+-----------+-------+\n| id | student_id | name | class_Id | classname | score |\n+------+------------+--------+----------+-----------+-------+\n| 2 | 2005002 | \u674e\u56db | 0001 | \u6570\u5b66 | 89 |\n| 3 | 2005001 | \u5f20\u4e09 | 0001 | \u6570\u5b66 | 69 |\n+------+------------+--------+----------+-----------+-------+\n2 rows in set (Elapsed: 00:00:00.00)\n<\/code><\/pre>\n\n\n\n<\/span>\u5173\u8054\u5220\u9664<\/span><\/h3>\n\n\n\n\u8be5\u65b9\u6cd5\u662f\u5148\u62ff\u5230\u6709\u91cd\u590d\u503c\u7684max(id),\u7136\u540e\u901a\u8fc7\u591a\u8868\u5173\u8054\u5220\u9664\u7684\u65b9\u6cd5\uff0c\u5c06\u5176\u5b83\u5b57\u6bb5\u76f8\u7b49\uff0c\u4f46id\u5c0f\u4e8emax(id)\u7684\u884c\u5220\u9664\u3002<\/p>\n\n\n\n
gbase> select student_id,name,class_id,classname,score,max(id) from exam_2 group by student_id,name,class_id,classname,score having count(*) >1;\n+------------+--------+----------+-----------+-------+---------+\n| student_id | name | class_id | classname | score | max(id) |\n+------------+--------+----------+-----------+-------+---------+\n| 2005001 | \u5f20\u4e09 | 0001 | \u6570\u5b66 | 69 | 3 |\n+------------+--------+----------+-----------+-------+---------+\n1 row in set (Elapsed: 00:00:00.05)\n\n\u5982\u4e0b\u662f\u5b8c\u6574SQL\n\ngbase> delete a from exam_2 a inner join (select student_id,name,class_id,classname,score,max(id) maxid from exam_2 group by student_id,name,class_id,classname,score having count(*) >1)b on a.student_id=b.student_id and a.name=b.name and a.class_id=b.class_id and a.classname=b.classname and a.score=b.score and a.id<b.maxid;\nQuery OK, 1 row affected (Elapsed: 00:00:00.17)\ngbase> select * from exam_2;\n+------+------------+--------+----------+-----------+-------+\n| id | student_id | name | class_Id | classname | score |\n+------+------------+--------+----------+-----------+-------+\n| 2 | 2005002 | \u674e\u56db | 0001 | \u6570\u5b66 | 89 |\n| 3 | 2005001 | \u5f20\u4e09 | 0001 | \u6570\u5b66 | 69 |\n+------+------------+--------+----------+-----------+-------+\n2 rows in set (Elapsed: 00:00:00.00)\n<\/code><\/pre>\n\n\n\n<\/span>Summary<\/span><\/h2>\n\n\n\n\u65b9\u6cd51\u8bed\u6cd5\u7b80\u5355\u5bb9\u6613\u7406\u89e3\uff0c\u65b9\u6cd52\u8bed\u6cd5\u590d\u6742\u3002\u4f46\u90fd\u662f\u901a\u8fc7join\u7684\u65b9\u5f0f\uff0c\u5c06\u4e0d\u5339\u914d\u7684\u5220\u9664\u3002<\/p>\n\n\n\n
\u5728\u91cd\u590d\u6570\u636e\u7684\u6bd4\u4f8b\u6781\u4f4e\u65f6\uff0c\u6bd4\u59821000\u7528\u6237\u4e07\u884c\u91cc\u53ea\u6709100\u7528\u6237\u91cd\u590d\u7684\uff0c\u5219\u65b9\u6cd52\u53ef\u4ee5\u51cf\u5c11\u4e00\u4e9bjoin\u7684\u6570\u636e\u8d1f\u8f7d\u3002<\/p>","protected":false},"excerpt":{"rendered":"
\u672c\u6587\u6839\u636e\u7f51\u4e0a\u5e38\u89c1\u7684SQL\u9762\u8bd5\u9898\uff0c\u5220\u9664\u9664\u4e86\u81ea\u52a8\u7f16\u53f7\u4e0d\u540c, \u5176\u4ed6\u90fd\u76f8\u540c\u7684\u5b66\u751f\u5197\u4f59\u4fe1\u606f\uff0c\u7ed9\u51fa\u5206\u6790\u548c\u5728GBase 8a\u6570\u636e\u5e93\u96c6\u7fa4\u4e0a\u7684\u6267\u884c\u7ed3\u679c\u3002<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[81],"class_list":["post-3785","post","type-post","status-publish","format-standard","hentry","category-gbase8a","tag-81"],"_links":{"self":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/3785","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/comments?post=3785"}],"version-history":[{"count":8,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/3785\/revisions"}],"predecessor-version":[{"id":7566,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/3785\/revisions\/7566"}],"wp:attachment":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/media?parent=3785"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/categories?post=3785"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/tags?post=3785"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}