Table Creation

• 步骤

  1. Design, 各field所记录的数据类型
  2. Refinement, 将filed细化，找出或创建primary key
  3. Building SQL Schema Statements)

• 设置输入限制: eye_color char(2) CHECK (eye_color IN ('BR','BL','GR')); or eye_color ENUM('BR','BL','GR');

• CONSTRAINT

  • PRIMARY KEY ()
  • FOREIGN KEY () 加入foreign key限制后，无法在表中对foreign key对应的field进行增改.