select name from
(select name from table1
union
select name from table2
union
select name from table3
union
select name from table4)
group by name
(select name from table1
union
select name from table2
union
select name from table3
union
select name from table4)
group by name
union
select name from table2
union
select name from table3
union
select name from table4;
(select name from table1
union
select name from table2
union
select name from table3
union
select name from table4)
group by name
FROM table1
INTERSECT
SELECT name
FROM table2
INTERSECT
SELECT name
FROM table3;