Error message:

Operation failed, could not execute statement; SQL [n/a]; nested exception is org.hibernate.exception.DataExcepti

The reason is the limitation of database field length!!

It is also possible that this table field does not exist. It mainly depends on SQL   There are entity class mappings and table structures

Operation failed, query did not return a unique result: 2; nested exception is javax.

This is the interface originally returned an object, but two pieces of data were queried in the database