查詢表中重復數據 select * from employee where employeeId in (select employeeId from employee group by employeeId having count(employeeId) > 1) 刪除表中多余 ...
查詢表中重復數據。select from people where peopleId in select peopleId from people group by peopleId having count peopleId gt 刪除表中多余的重復記錄,重復記錄是根據單個字段 peopleId 來判斷,只留有rowid最小的記錄 delete from people where people ...
2016-08-31 22:01 0 14502 推薦指數:
查詢表中重復數據 select * from employee where employeeId in (select employeeId from employee group by employeeId having count(employeeId) > 1) 刪除表中多余 ...
來自 王濤 同志的指導 DELETE FROM product WHERE searchdate IN (SELECT sd FROM (SELECT a.searchdate sd FROM pr ...
表名:hztj 字段名:edxzqhdm ,sdxzqhdm 1.查出某一列數據中重復的,以sdxzqhdm為例 select * from hztj a where (a.sdxzqhdm) in (select sdxzqhdm from hztj group by sdxzqhdm ...
刪除數據庫中重復的記錄,只保留一條 DELETE FROM tb_gps_records WHERE id NOT IN (SELECT bid FROM (SELECT min(id) as bid FROM tb_gps_records GROUP BY busNo,longitude ...
create table Student( ID varchar(10) not null, Name varchar(10) not null, ); insert ...
在執行語句時難免會輸入相同的數據,這些重復記錄不但沒有用,還可能導致數據庫占用大量資料或導致數據庫查詢索引無效。 如果在建表的時候沒有設置主鍵或unique索引,那么插入完全重復的數據是不會報錯的,結果就是無法修改記錄行或者刪除記錄行。通過SQL語句可以實現刪除表中重復數據。 所有字段均重復 ...
在幾千條記錄里,存在着些相同的記錄,如何能用SQL語句,刪除掉重復的呢1、查找表中多余的重復記錄,重復記錄是根據單個字段(peopleId)來判斷 select * from people where peopleId in (select peopleId from people ...
select train_code,count(1) from tb_ask_trainbodyroadtrain group by train_code having count(1) >1 ...