1. Mapper method 'com.example.demo.mapper.userMapper.create attempted to return null from a method with a primitive return type (int).] with root cause
是新增用户信息接口，发现用户信息已经成功插入数据库，但是页面提示
There was an unexpected error (type=Internal Server Error, status=500).
Mapper method 'com.example.demo.mapper.userMapper.create attempted to return null from a method with a primitive return type (int).
出错原因很简单,mapper.xml 映射文件中，新增记录应该用insert，我懒，直接复制了上面的select， 然后搓了很久。。