严重: Servlet.service() for servlet [spring-mvc] in context with path [/learn] threw exception [Request processing failed; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement] with root causecom.mysql.j…

严重: Servlet.service() for servlet jsp threw exceptioncom.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '88888888' for key 'PRIMARY'    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) …

### Error updating database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'qingmu' for key 'PRIMARY' ### The error may involve com.qingmu2.core.dao.seller.SellerDao.insertSelective-Inline ### The…

情景: Mapper.xml定义连表查询,如果sql的字段名中有sql关键字,会导致PageHelper插件出现 com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Duplicate column name 'Id' 这样的错误. 将具有关键字性质的字段名前后加入 ` 符号即可,例如 a.`Id`,a.`Vin`…

MySQL完整性约束破坏异常:com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException 在单向多对一关联关系中,如果A 持有 B 的引用(即A是多端,B是一端),也就是A 的外键列指向了B 的主键.那么此时如果先删除B, 再删除A(即先删除一端,再删除A端).那么就会抛出上述异常. Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConst…

### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'org_mer_id' in where clause is ambiguous ### The error may exist in class path resource [mapper/StatisticsPeriodTaskMapper.xml] ##…

问题:同样的代码,只能插入一组值,第二组值插入不了 解决:开始我将app_id作为主键,但很明显,同一个app_id会有不同的index,而同一个index也可能对应不同的app_id,因此只能添加一个id作为主键.开始只是将id作为主键,但这样需要每次将id添加进去,这是不现实的,因为不会每次都知道id到多少了:因此给了id一个默认值,这样也不现实,因为当组添加时id会相同,而id作为主键应该每次都不同, 所以最后将id选择AI(Auto Increment),自动增长,解决问题.…

今天在使用mysql数据库查找数据的时候报错,错误信息如下: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'dd' in 'where clause' at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newI…

09:00:30.307 [http-8080-6] ERROR org.hibernate.transaction.JDBCTransaction -JDBC begin failed com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet successfully received from the server was 56,237,340 mi…

本文转自:http://blog.csdn.net/zmzsoftware/article/details/6835604 MySQL第二天早上第一次连接超时报错,解决方法com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link fa…