java上傳文件到另一臺(tái)服務(wù)器 Mysql數(shù)據(jù)庫(kù)中多條重復(fù)數(shù)據(jù),如何只刪除一條?
Mysql數(shù)據(jù)庫(kù)中多條重復(fù)數(shù)據(jù),如何只刪除一條?列出要保留的記錄ID,可以把這個(gè)結(jié)果寫(xiě)到一個(gè)臨時(shí)表t1中: SELECT MAX(id) AS max_id FROM pedigree GROUP B
Mysql數(shù)據(jù)庫(kù)中多條重復(fù)數(shù)據(jù),如何只刪除一條?
列出要保留的記錄ID,可以把這個(gè)結(jié)果寫(xiě)到一個(gè)臨時(shí)表t1中: SELECT MAX(id) AS max_id FROM pedigree GROUP BY number然后:DELETE FROM pedigree WHERE id NOT IN (SELECT id FROM t1)也就是:delete from pedigree where id not in(select * from pedigree where group by number)。pedigree where id not in(select max(id) from pedigree where group by number having count(id) > 0) 查詢結(jié)果是否符合刪除要求!