最近写了下英文搜索的小偷，为了让蜘蛛更好的享受链接的乐趣，因此使用了入库处理，将最近的搜索写入到mysql中，同时在首页调用这些查询数据，就可以达到网站地图的效果，但是弊端也出现了了，那就是重复记录的问题。 在网上找到一段实例，经过修改发现可行，现将代码公布如下：Copy to Clipboard引用的内容：[www.bkjia.com] $link=mysql_connect(‘localhost’,’root’,’1234’); //得到MySQL数...
mysql 表名是tongxunlu 字段是id sXingMing sXingBie dtShengRi 因为重复插入了，几份数据，想删除重复的 回复讨论(解决方案) 举例说明，怎么判断重复的。 手动删除。。 可以直接判断sXingMing sXingBie dtShengRi这几个字段值是否相同，然后再根据需要进行删除 删除重复记录 delete from tongxunlu a where rowid not in(select max(rowid) from tongxunlu where id=a.id and sXingMing=a.sXingMing and sX...
插入不重复记录～～～求一mysql语句～～～表结构很简单：SQL code -------------------------------- id | cat | article --------------------------------1 abc 12 aaa 23 ccc 1 -------------------------------- 其中id是唯一主键，AUTO_INCREMENT，对于插入记录来讲没什么用。现在要插入一些记录，当新记录的cat和article_id在原先数据中都未出现时才允许插入。比如cat=...
mysql怎么删除重复记录表名是tongxunlu 字段是id sXingMing sXingBie dtShengRi 因为重复插入了，几份数据，想删除重复的mysql分享到：------解决方案--------------------先说多少条数据。 数据不多的话，把数据表备份出来，原来的表清空，foreach扫一遍备份数据表，把不重复的的插入到原来的表中。 这样就解决问题了，没必要搞那么高深。
查询及删除重复记录的方法(一)1、查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断select * from peoplewhere peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1) 2、删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有一个记录delete from peoplewhere peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1...
TABLE TabTest (`id` INT(11) NOT NULL AUTO_INCREMENT ,`factorA` VARCHAR(255) NOT NULL DEFAULT ‘ ‘,`factorB` VARCHAR(255) NOT NULL DEFAULT ‘ ‘,`factorC` DECIMAL(10,2) NOT NULL DEFAULT 0,`remark` VARCHAR(255) NOT NULL DEFAULT ‘ ‘, PRIMARY KEY (`id`) ) ENGINE=INNODB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8 COMMENT=‘‘;INSERT INTO TabTest(factorA, factorB, factorC, remark) SELECT ‘A1‘, ‘B1‘...
mysql删除重复记录的原理是： 将需要比较的列放到group by后，取出主键的最小值，再删除不在这个临时表主键的行 命令行格式如下 delete from users where id not in ( select id from ( select min(id) from users group by name,sex ) as tmp); 需要比较的列是name和sex，取出id后再从users表中取出id查看该id是否在临时表中存在，不存在则删除掉。mysql 删除重复记录标签：本文系统来源：http://my.oschina.net/jiangmiti...
//例一：select name1,count(*) as count from table_name group by name1 having count>1;//例二：select name1,name2 ,count(name1) as countb,count(name2) as count from table_name group by name1,name2 having count>1 and countb >1; mysql 数据表中查找重复记录标签：本文系统来源：http://www.cnblogs.com/langtianya/p/5086651.html
from `jb_postcontent` where id not in(select min(id) from (select * from `jb_postcontent`) as t group by t.id);网上搜索的大部分都是如下这样delete from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1) and rowid not in (select min(rowid) from people group by peopleId having count(peopleId )>1) 结果你会发现，mysql报错，因为不能更新用于子查询...
3、查找表中多余的重复记录（多个字段）select * from vitae awhere (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1) 4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录delete from vitae awhere (a.peopleId,a.seq) in (select peopleId,seq from vitae group by peopleId,seq having count(*) > 1)and rowid not in (select min(rowid) from vitae group by pe...
方法1： 1、创建一个临时表，选取需要的数据。 2、清空原表。 3、临时表数据导入到原表。 4、删除临时表。 mysql> select * from student; +----+------+ | ID | NAME | +----+------+ | 11 | aa | | 12 | aa | | 13 | bb | | 14 | bb | | 15 | bb | | 16 | cc | +----+------+ 6 rows in setmysql> create temporary table temp as select min(id),name from student group by name; Query OK, 3 rows affected Records: 3 Duplic...
(一)1、查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断 select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)2、删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有一个记录 delete from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1) and min(id) not in ...
检查重复code1 select count(identity) num, identity from event_log where code=‘code1‘ group by identity having count(identity) > 1 order by num desc删除重复记录DELETE FROM event_log WHERE `code`=‘code1‘ AND identity IN (SELECT identity from (SELECT identity FROM event_log WHERE code=‘code1‘ GROUP BY identity HAVING count(identity) > 1) a ) AND id NOT IN (SELECT keepId FROM (SELECT min(id) k...
，很容易:SELECT min(`id`),`name` FROM `table` GROUP BY `name`; 但是这样并不能得到说有重复字段的id值。（只得到了最小的一个id值）查询哪些字段是重复的也容易:SELECT `name`,count(`name`) as count FROM `table` GROUP BY `name` HAVING count(`name`) >1 ORDER BY count DESC; 但是要一次查询到重复字段的id值，就必须使用子查询了，于是使用下面的语句。SELECT `id`,`name` FROM `table` WHERE `name` in (SELECT `name`F...
代码如下:select distinct name from A 执行后结果如下： 示例2 复制代码 代码如下:select distinct name, id from A 执行后结果如下：实际上是根据“name+id”来去重，distinct同时作用在了name和id上，这种方式Access和SQL Server同时支持。 示例3：统计 复制代码 代码如下:select count(distinct name) from A; --表中name去重后的数目， SQL Server支持，而Access不支持 select count(distinct name, id) from A; --SQL ...