the hibernate many, many-to-many (annotation mode)

Configure-to-many:

@OneToMany(mappedBy="grade", cascade={ CascadeType.ALL })

1, mappedBy, equivalent to the inverse = true, reverse, grade is more than one entity class attribute names
2, cascade cascade operation:
CascadeType.REMOVE : cascade delete
CascadeType.PERSIST : cascade saves
CascadeType.MERGE : Cascade update
CascadeType.REFRESH : cascading refresh
CascadeType.ALL : cascading all actions
configured many-to

@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="gradeId")

1, JoinColumn specified foreign key column
2, fetch delay loading strategy specified, the default is of EAGER, i.e. load immediately, can be set to LAZY

Examples