Using mySQL to compare 2 tables - mysql

Question

I'm trying to compare 2 mySQL tables to find differences between them. A record may be found in TableA but not in TableB, or vice versa.
My tables are as follows:
TableA
Name A1 A2 B1 B2
------------------------
John 11 12 21 23
John 11 12 21 22
John 33 34 31 33
Mary 41 42 54 55
Mary 71 72 81 82
Mary 41 42 51 52
TableB
Name A1 A2 B1 B2 C D
---------------------------------
John 11 12 21 22 999 999
John 21 23 11 12 999 999
John 31 32 33 34 999 999
Mary 41 42 51 52 999 999
Mary 54 55 41 42 999 999
Columns A1 and A2 is considered a group, and B1 and B2 considered another group. For a record to be considered found in both tables, I need
- TableA(A1,A2) = TableB(A1,A2) AND TableA(B1,B2) = TableB(B1,B2)
OR
- TableA(A1,A2) = TableB(B1,B2) AND TableA(B1,B2) = TableB(A1,A2)
For the 2 tables, above, I would compare all of TableA's John to all of TableB's John, and all of TableA's Mary to all of TableB's Mary.
I should get the output
Name A1 A2 B1 B2 C D
-----------------------------------------------
John 31 32 33 34 999 999 (from TableB)
Mary 41 42 54 55 (from TableA)
Mary 71 72 81 82 (from TableA)
Mary 54 55 41 42 999 999 (from TableB)
I'm new to mySQL, and the above seems so complicated to me that I'm not even sure where to start.
I would really appreciate any help on this.

Answer 1

If I understood you correctly, you need to issue two queries: one for finding records from TableA not existing in TableB, and second one for the opposite situation. Note that in one case it's LEFT JOIN and in the second case it's RIGHT JOIN.
SELECT a.*, '' AS C, '' AS D, '(from TableA)' AS 'table'
FROM TableA AS a
LEFT JOIN TableB AS b
ON ((a.A1 = b.A1 AND a.A2 = b.A2 AND a.B1 = b.B1 AND a.B2 = b.B2)
OR (a.A1 = b.B1 AND a.A2 = b.B2 AND a.B1 = b.A1 AND a.B2 = b.A2))
AND a.Name = b.Name
WHERE b.Name IS NULL
UNION
SELECT b.*, '(from TableB)' AS 'table'
FROM TableA AS a
RIGHT JOIN TableB AS b
ON ((a.A1 = b.A1 AND a.A2 = b.A2 AND a.B1 = b.B1 AND a.B2 = b.B2)
OR (a.A1 = b.B1 AND a.A2 = b.B2 AND a.B1 = b.A1 AND a.B2 = b.A2))
AND a.Name = b.Name
WHERE a.Name IS NULL