将内容实体中关系的配置更改为:
@JoinTable(name = "content_tag", joinColumns = @JoinColumn(name = "content_id"), inverseJoinColumns = @JoinColumn(name="tag_id"))

将内容实体中关系的配置更改为:
@JoinTable(name = "content_tag", joinColumns = @JoinColumn(name = "content_id"), inverseJoinColumns = @JoinColumn(name="tag_id"))