mysql删除重复记录只保留一条
@钱泥3633：mysql中有重复的数据,怎么删除,只留下一条就行了.
离瞿18384712734…… 要是有唯一标识 首先找出 distinct max(唯一) 在delete 你懂得 . 要是没有唯一标识 那就distinct 存临时,在 delete - insert
@钱泥3633：Mysql数据库中多条重复数据,如何只删除一条? -
离瞿18384712734…… 列出要保留的记录ID,可以把这个结果写到一个临时表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 ...
@钱泥3633：mysql 删除字段内的重复内容但保留一条 该怎么写? -
离瞿18384712734…… select * from 表名 where 字段名 in (select 字段名 from 表名 group by 字段名 having count(字段名) > 1)
@钱泥3633：求一mysql语句,去掉数据库里某个字段相同记录,只保留一个. -
离瞿18384712734…… select distinct(字段名) from 表名
@钱泥3633：mysql删除重复数据只保留一条 -
离瞿18384712734…… delete from table a where (a.catid ,a.title ) in (select catid ,title from table group by catid ,title having count(*) > 1) and 自动递增的字段 not in (select min(自动递增的字段) from table group by catid ,title having count(*)>1) and modelid=3
@钱泥3633：mysql中删除重复的记录,只留下一条!!
离瞿18384712734…… 起初表不应该这样设计 至少得有个主键吧 记录完全重复 囧 mysql code: create table tmp select distinct * from mytable; drop table mytable; create table mytable select * from tmp; drop table tmp;
@钱泥3633：MySQL一条语句将表中重复记录删除到只剩一条 -
离瞿18384712734…… 删除重复行sql,将会删除所用重复的数据,保留一条不重复的数据 ALTER IGNORE TABLE your_table ADD UNIQUE INDEX idx_name (cols_a, cols_b, cols_c, cols_d, cols_e);
@钱泥3633：mysql如何删除没有主键的重复数据,只保留一条 -
离瞿18384712734…… 只能用变通的办法 假设表有N1,N2,N3三个字段,都是INT类型,表名是NUMBER,执行如下语句:DECLARE @TB TABLE (N1 INT,N2 INT,N3 INT); INSERT INTO @TB SELECT TOP 1 * FROM NUMBER; DELETE NUMBER; INSERT INTO NUMBER SELECT * FROM @TB; SELECT * FROM NUMBER; 这样就OK了!
@钱泥3633：mysql如何去掉数据库中重复记录 -
离瞿18384712734…… 1. 查询需要删除的记录,会保留一条记录. select a.id,a.subject,a.RECEIVER from test1 a left join (select c.subject,c.RECEIVER ,max(c.id) as bid from test1 c where status=0 GROUP BY RECEIVER,SUBJECT having count(1) >1) b on a.id2. 删除...
@钱泥3633：求MYSQL中某字段内的重复数据以及删除重复保留一条 -
离瞿18384712734…… delete from tbl_vod where id not in (select id from (select id from tbl_vod group by d_name having count(d_name)>1) as a) mysql不支持在同一个表查询之后,做修改、删除操作. 删除的思路是, 1、select id from tbl_vod group by d_name having...
离瞿18384712734…… 要是有唯一标识 首先找出 distinct max(唯一) 在delete 你懂得 . 要是没有唯一标识 那就distinct 存临时,在 delete - insert
@钱泥3633：Mysql数据库中多条重复数据,如何只删除一条? -
离瞿18384712734…… 列出要保留的记录ID,可以把这个结果写到一个临时表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 ...
@钱泥3633：mysql 删除字段内的重复内容但保留一条 该怎么写? -
离瞿18384712734…… select * from 表名 where 字段名 in (select 字段名 from 表名 group by 字段名 having count(字段名) > 1)
@钱泥3633：求一mysql语句,去掉数据库里某个字段相同记录,只保留一个. -
离瞿18384712734…… select distinct(字段名) from 表名
@钱泥3633：mysql删除重复数据只保留一条 -
离瞿18384712734…… delete from table a where (a.catid ,a.title ) in (select catid ,title from table group by catid ,title having count(*) > 1) and 自动递增的字段 not in (select min(自动递增的字段) from table group by catid ,title having count(*)>1) and modelid=3
@钱泥3633：mysql中删除重复的记录,只留下一条!!
离瞿18384712734…… 起初表不应该这样设计 至少得有个主键吧 记录完全重复 囧 mysql code: create table tmp select distinct * from mytable; drop table mytable; create table mytable select * from tmp; drop table tmp;
@钱泥3633：MySQL一条语句将表中重复记录删除到只剩一条 -
离瞿18384712734…… 删除重复行sql,将会删除所用重复的数据,保留一条不重复的数据 ALTER IGNORE TABLE your_table ADD UNIQUE INDEX idx_name (cols_a, cols_b, cols_c, cols_d, cols_e);
@钱泥3633：mysql如何删除没有主键的重复数据,只保留一条 -
离瞿18384712734…… 只能用变通的办法 假设表有N1,N2,N3三个字段,都是INT类型,表名是NUMBER,执行如下语句:DECLARE @TB TABLE (N1 INT,N2 INT,N3 INT); INSERT INTO @TB SELECT TOP 1 * FROM NUMBER; DELETE NUMBER; INSERT INTO NUMBER SELECT * FROM @TB; SELECT * FROM NUMBER; 这样就OK了!
@钱泥3633：mysql如何去掉数据库中重复记录 -
离瞿18384712734…… 1. 查询需要删除的记录,会保留一条记录. select a.id,a.subject,a.RECEIVER from test1 a left join (select c.subject,c.RECEIVER ,max(c.id) as bid from test1 c where status=0 GROUP BY RECEIVER,SUBJECT having count(1) >1) b on a.id2. 删除...
@钱泥3633：求MYSQL中某字段内的重复数据以及删除重复保留一条 -
离瞿18384712734…… delete from tbl_vod where id not in (select id from (select id from tbl_vod group by d_name having count(d_name)>1) as a) mysql不支持在同一个表查询之后,做修改、删除操作. 删除的思路是, 1、select id from tbl_vod group by d_name having...
