Suppliers - Projects - Parts database

CREATE TABLE parts (
  PartID CHAR(4) CONSTRAINT parts_pk PRIMARY KEY,
  name      VARCHAR2(32) CONSTRAINT parts_notnull_name NOT NULL,
  color     VARCHAR2(12) DEFAULT 'Red',
  weight    NUMBER(4,1),
  price     NUMBER(8,2) DEFAULT 19.99,
  min_price NUMBER(8,2),
  CONSTRAINT parts_check_prices CHECK ( min_price < price )
);

CREATE TABLE suppliers (
  sid    CHAR(4) CONSTRAINT suppliers_pk PRIMARY KEY,
  name   VARCHAR(32) CONSTRAINT suppliers_notnull_name NOT NULL,
  city   VARCHAR(24) DEFAULT 'London',
  sttaus NUMBER(3, 0),
  CONSTRAINT suppliers_check_status CHECK ( status BETWEEN 0 AND 100 )
);

CREATE TABLE projects (
  ProjectID   CHAR(4),
  ProjectName VARCHAR2(32) NOT NULL,
  city        VARCHAR2(24) NOT NULL,
  CONSTRAINT Project_PK PRIMARY KEY (ProjectID)
);

CREATE TABLE orders (
  SupplierID CHAR(4) CONSTRAINT orders_supp_fk REFERENCES suppliers ON DELETE CASCADE,
  PartID     CHAR(4) CONSTRAINT orders_part_fk REFERENCES parts ON DELETE CASCADE,
  ProjectID  CHAR(4) CONSTRAINT orders_proj_fk REFERENCES projects ON DELETE CASCADE,
  quantity   number(4,0) DEFAULT 5,
  status     VARCHAR2(16 CHAR),
  CONSTRAINT orders_pk PRIMARY KEY (SupplierId, PartID, ProjectID),
  CONSTRAINT orders_check_qty CHECK (quantity > 0)
);