root:test> insert ignore into t3 (c1,c2,c3) values(5,‘cc’,4),(6,‘dd’,5); Query OK, 1 row affected, 1 warning (0.01 sec) Records: 2 Duplicates: 1 Warnings: 1 1. 2. 如下,可以看到只插入了(6,‘dd’,5)这条,同时有一条warning提示有重复的值。 复制代码 root:test> show warn...
在MySQL中删除重复记录可以通过以下步骤实现: 1. 首先,使用SELECT语句和GROUP BY子句来确定哪些记录是重复的。例如,假设我们有一个名为"table_name"的表,其中包含一个名为...
执行如下命令就能分析日志: #python mysql_filter_slow_log.py /var/lib/mysql/hostname-slow.log --no-duplicates --sort-execution-count --top=10 功能上类似于mysqldumpslow,但是多出了很多查询时间的统计信息,包括平均、最大、累计等,此外,还对输出内容排版和格式化。 4、myprofi sourceforge上提供的纯php写...
| id | int(4) | NULL | NO | PRI | NULL | auto_increment | select,insert,update,references | 主键 | | name | varchar(20) | utf8_general_ci | NO | | NULL | | select,insert,update,references | 姓名 | | sex | int(4) | NULL | NO | | 0 | | select,insert,update,referenc...
I have this insert into select duplicate key update query but after executing it twice, the amount of rows get doubled. Stack overflow wants me to add text, so I'm just writing stuff at this moment because I dont think you guys need more explanation as this query is quite self explanato...
语法一:select 列名 from 表1 inner join 表2 on 表公共字段=表2.公共字段 语法二:select 列名 from 表1,表2 where 表公共字段=表2.公共字段 例题 方法一: mysql> select stuname,stusex,writtenexam,labexam from stuinfo inner join stumarks on stuinfo.stuno=stumarks.stuno; ...
Records: 3 Duplicates: 0 Warnings: 0 # 查询并打印记录 MySQL localhost:33060+ ssl Py > result = session.run_sql('SELECT * FROM users') MySQL localhost:33060+ ssl Py > print(result.fetch_all()) [ [1, "Alice", 30], [2, "Bob", 25], ...
Records: 0 Duplicates: 0 Warnings: 0 mysql> explain select name from s1 where id=1000; #命中辅助索引,但是未覆盖索引,还需要从聚集索引中查找name +---+---+---+---+---+---+---+---+---+---+---+---+ | id | select_type | table | partitions | type | possible_keys | key...
Records: 0 Duplicates: 0 Warnings: 0 #添加关联删除和关联更新的操作:当删除主表数据的时候,从表中有关的数据都跟着删除,当主表的关系字段修改的时候,从表对应的关系字段的值也更着更新。 alter table 从表 add foreign key(从表字段) references 主表(主表字段) on delete cascade on update cascade; ...
Ya know, I didn't ask for help with INSERT IGNORE or ON DUPLICATE KEY specifically. I asked for help avoiding duplicates. I already came up with a solution using python to execute what I wanted successfully. Pretty sure, however, this is more effecient: ...