create table employee (
   employeeid integer
,  name varchar (80 ) not null
,  primary key (employeeid)
)

create table object (
   objectid integer
,  name varchar (80 ) not null
,  primary key (objectid)
)

create table visit (
   visitid integer
,  objectid integer not null
,  date date not null
,  primary key (visitid)
,  foreign key (objectid) references object on delete restrict
)

create table visitemployee (
,  visitid integer not null
,  employeeid integer not null
,  primary key (visitid, employeeid)
,  foreign key (visitid) references visit on delete cascade
,  foreign key (employeeid) references employee on delete restrict
)

select distinct object.name
from visitemployee 
     inner join visit on visitemployee.visitid = visit.visitid
         inner join object on visit.objectid = object.objectid
where visitemployee.employeeid =  1