Several common errors when using MP

One, the automatic insertion of the date reports null, but the MetaObjectHandler has been configured

Description:

Solution:
as followsThe metaobject has been configured or an error is reported.

The actual cause of the problem is the corresponding attribute of the entity classThe type is not LocalDateTime but Date, which should be changed to LocalDateTime.

Change Date to LocalDateTime

Second, the primary key id has no error and no default value

Description:
org.springframework.dao.DataIntegrityViolationException:
Error updating database. Cause: java.sql.SQLException: Field 'subject_parent_id' doesn't have a default value
Resolved;
The id annotation should be set to auto-increment in the database

Third, Parameter ‘MP_OPTLOCK_VERSION_ORIGINAL’ not found.

When the updateById method is used and the updated field contains the version field, the MP optimistic lock will be used by default.
There will be one more version condition in sql.

Solution:
Type 1: UpdatedDo not include the version field in the field.
Second: You can use the update method of Mapper.