Foreign key constraint failure when trying to insert because of key change

Question

I have a Content object which refers to a set of Tag objects in a ManyToMany relationship. As part of persisting a new Content object I look in PostgreSQL to see if the Tag alr

Answer 1

change the configuration of your relation in content entity to this:

@JoinTable(name = "content_tag",
        joinColumns = @JoinColumn(name = "content_id"),
        inverseJoinColumns = @JoinColumn(name="tag_id")
)

Answer 2

This caused by transaction,U can't read uncommitted data, U may commit a transaction after U create a line of 'tag'.