DuplicateKeyException异常处理，向数据库添加数据失败

问题描述

向数据库中添加数据失败

问题报错

### Error updating database.  Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '0-0' for key 'PRIMARY'
### The error may involve com.leyou.item.mapper.BrandMapper.insertCategoryBrand-Inline
### The error occurred while setting parameters
### SQL: insert into tb_category_brand(category_id, brand_id) values (category_id=?,brand_id=?)
### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '0-0' for key 'PRIMARY'
; ]; Duplicate entry '0-0' for key 'PRIMARY'; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '0-0' for key 'PRIMARY'] with root cause

问题原因

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry ‘0-0’ for key ‘PRIMARY’
说明在数据库中这一列，它为空！因为主键在数据库中不能为空，所以出现下面异常；就需要把主键设置为不为空就可以解决了

数据库中表的数据