Разработать и нормализовать БД

CREATE TABLE subdivisions
( 
    subdiv_id            INTEGER IDENTITY ( 1,1 ) ,
    subdivision_code     INTEGER  NOT NULL ,
    subdivision_name     VARCHAR(20)  NULL 
)
GO
 
 
 
ALTER TABLE subdivisions
    ADD CONSTRAINT XPKsubdivisions PRIMARY KEY  CLUSTERED (subdiv_id ASC)
GO
 
 
 
CREATE TABLE visits
( 
    visit_id             INTEGER IDENTITY ( 1,1 ) ,
    visit_date           smalldatetime  NOT NULL ,
    worker_id            INT  NOT NULL 
)
GO
 
 
 
ALTER TABLE visits
    ADD CONSTRAINT XPKvisits PRIMARY KEY  CLUSTERED (visit_id ASC)
GO
 
 
 
CREATE TABLE workers
( 
    worker_id            INT IDENTITY ( 1,1 ) ,
    fio                  VARCHAR(100)  NOT NULL ,
    phone                VARCHAR(20)  NOT NULL ,
    pasport              VARCHAR(10)  NOT NULL ,
    address              VARCHAR(150)  NOT NULL ,
    subdiv_id            INTEGER  NOT NULL 
)
GO
 
 
 
ALTER TABLE workers
    ADD CONSTRAINT XPKworkers PRIMARY KEY  CLUSTERED (worker_id ASC)
GO
 
 
 
 
ALTER TABLE visits
    ADD CONSTRAINT worker2visit FOREIGN KEY (worker_id) REFERENCES workers(worker_id)
        ON DELETE NO ACTION
        ON UPDATE NO ACTION
GO
 
 
 
 
ALTER TABLE workers
    ADD CONSTRAINT subdiv2worker FOREIGN KEY (subdiv_id) REFERENCES subdivisions(subdiv_id)
        ON DELETE NO ACTION
        ON UPDATE NO ACTION
GO