把STring类型转成blob类型存到数据库

Question

Type handler was null on parameter mapping for property 'userImg. It was either not specified and/or could not be found for the javaType (java.sql.Blob) : jdbcType (null) combination.

The error may exist in com/example/dao/UsersDao.java (best guess)把STring类型转成blob类型存到数据库为什么会报这个错

Answer 1

Users这个实体类的属性userImg的类型是什么？String还是Blob？