Can a @ManyToOne JPA relation be null?

Question

The @ManyToOne associations are optional by default, so you don’t need to set anything if you want them to be nullable.

However, because you set the optional=false attribute, you made it mandatory.

So instead of:

@ManyToOne(optional = false, fetch = FetchType.LAZY)

Set it like this:

@ManyToOne(fetch = FetchType.LAZY)

The optional is true by default.

On the other hand, the @Column(nullable=true) is to instruct the DDL generation tool to include a NULL SQL column type constraint.