先创建两个entity
因为是多个t主题(topic)对应一个作者(author)
所以topic要有个外键author_id参照author的id
那么双击topic,创建一个column author_id 并且在M上选对勾:意思是这个外键必须有值(帖子肯定是要有个作者发啊,不能是null)
Mandatory |
When selected, indicates a column that must be assigned a not null value |
然后点击reference,并连上2个entity
双击连接线,parent table即是author,而child table 是topic
Parent table |
Specifies the parent table of the reference. This table contains the primary key, or alternate key, linked by the reference. |
Child table |
Specifies the child table of the reference. This table contains the foreign key linked by the reference |
然后在joins里面把parent key 选为none,在指定外键列child table column
得到
如果praent key选为
那么你的外键就会是topic 主键加上author_id外键