全表去重，欄位有null值，保留最大id的資料
阿新 • • 發佈：2018-12-31
delete from budget_history_report where exists (select * from (select year ,season,schoolId,ifnull(gradeId, '') gradeId,ifnull(subjectId, '') subjectId,count(*),max(id) id from budget_history_report group by year ,schoolId,season,gradeId,subjectId having count(*) > 1) t2 where budget_history_report.year = t2.year and budget_history_report.season = t2.season and budget_history_report.schoolId = t2.schoolId and ifnull(budget_history_report.gradeId, '') = t2.gradeId and ifnull(budget_history_report.subjectId, '') = t2.subjectId and budget_history_report.id<t2.id);