240 发简信
IP属地:北京
  • Relational Algebra

    Generally, the result of a relational algebra operation is a new relatio...

  • Relationship Database Design

    Content Conceptual model - ERD Logical model - schema, data dictionary, ...

  • Resize,w 360,h 240
    Fan Trap and Chasm Trap

    Fan Trap (扇形陷阱) When an entity has more than one 1:N relationships, it i...