Counting duplicates?

Databases
1

I have several rows that may have non distinct column entries.
for example
c1|c2|c3
aa|bb|cc
aa|bb|dd
aa|xx|yy

I want a report that says aa occurs three times, bb twice, cc, dd, yy once therefore not important.
Even if I can do this one column at a time…

Select distinct count c1, c2, c3 … but not sure…

2 
SELECT data,sum(cnt) as cnt
FROM (
SELECT field1 as data ,count(*) as cnt FROM MY Table GROUP BY field1
UNION
SELECT field2 as data ,count(*) as cnt FROM MY Table GROUP by field2
UNION
SELECT field3 as data ,count(*) as cnt FROM MY Table GROUP by field3
} GROUP BY data
ORDER BY data
3

and if you want to know ONLY the duplicates
insert

HAVING cnt>1

before the ORDER statment

4

I’m sorry not wrapping my head…
If I want just column 1

mysql>
SELECT data,sum(cnt) as cnt FROM (SELECT id as data ,count(*) as cnt FROM machines GROUP BY id) group by data order by data;
ERROR 1248 (42000): Every derived table must have its own alias

5 
select data, count(*) as cnt from machines group by data having count(*) > 1
6

The OP indicated BB and Y which were in Col2 and Col3

7

And as Dave said, the “having count…” part is if you don’t want to see things that appear once

8

And in his 2nd post he said “If I want just column 1”

9

He did… after I had already posted my solution, upon which you printed the solution for a single column