/media/sda-magnetic/david/Dok-15-2023-11-27/informatik/www-intel-compute-stick-2022-06-13/027/mysqlmenge.txt

SELECT * FROM (SELECT * FROM a UNION SELECT * FROM b)x;

SELECT x FROM (SELECT x FROM a UNION SELECT x FROM b)x;
SELECT x FROM (SELECT x FROM a UNION SELECT x FROM c)x;
SELECT x FROM (SELECT x FROM b UNION SELECT x FROM c)x;

SELECT x FROM (SELECT x FROM a INTERSECT SELECT x FROM b)x;
SELECT x FROM (SELECT x FROM a INTERSECT SELECT x FROM c)x;
SELECT x FROM (SELECT x FROM b INTERSECT SELECT x FROM c)x;

(a OR b) AND c = a AND c OR b AND c
(a OR c) AND b = a AND b OR c AND b
(b OR c) AND a = b AND a OR c AND a

SELECT x FROM (
    SELECT x FROM c
    INTERSECT
    SELECT x FROM (SELECT x FROM a UNION SELECT x FROM b)x
)x ORDER BY x;

SELECT x FROM (
    SELECT x FROM (SELECT x FROM a INTERSECT SELECT x FROM c)x
    UNION
    SELECT x FROM (SELECT x FROM b INTERSECT SELECT x FROM c)x
)x ORDER BY x;


+------+
| x    |
+------+
| 0    |
| 10   |
| 12   |
| 13   |
| 2    |
| 3    |
| 4    |
| 5    |
| 7    |
| 8    |
+------+
10 rows in set (0.004 sec)


MariaDB [menge001]> SELECT x FROM (
    ->     SELECT x FROM (SELECT x FROM a INTERSECT SELECT x FROM c)x
    ->     UNION
    ->     SELECT x FROM (SELECT x FROM b INTERSECT SELECT x FROM c)x
    -> )x ORDER BY x;
+------+
| x    |
+------+
| 0    |
| 10   |
| 12   |
| 13   |
| 2    |
| 3    |
| 4    |
| 5    |
| 7    |
| 8    |
+------+
10 rows in set (0.004 sec)


(a OR c) AND b = a AND b OR c AND b

SELECT x FROM (
    SELECT x FROM b
    INTERSECT
    SELECT x FROM (SELECT x FROM a UNION SELECT x FROM c)x
)x ORDER BY x;

SELECT x FROM (
    SELECT x FROM (SELECT x FROM c INTERSECT SELECT x FROM b)x
    UNION
    SELECT x FROM (SELECT x FROM a INTERSECT SELECT x FROM b)x
)x ORDER BY x;


MariaDB [menge001]> SELECT x FROM (
    ->     SELECT x FROM (SELECT x FROM c INTERSECT SELECT x FROM b)x
    ->     UNION
    ->     SELECT x FROM (SELECT x FROM a INTERSECT SELECT x FROM b)x
    -> )x ORDER BY x;
+------+
| x    |
+------+
| 0    |
| 1    |
| 10   |
| 11   |
| 12   |
| 2    |
| 4    |
| 6    |
| 7    |
| 8    |
+------+
10 rows in set (0.005 sec)


MariaDB [menge001]> SELECT x FROM (
    ->     SELECT x FROM b
    ->     INTERSECT
    ->     SELECT x FROM (SELECT x FROM a UNION SELECT x FROM c)x
    -> )x ORDER BY x;
+------+
| x    |
+------+
| 0    |
| 1    |
| 10   |
| 11   |
| 12   |
| 2    |
| 4    |
| 6    |
| 7    |
| 8    |
+------+
10 rows in set (0.002 sec)


(b OR c) AND a = b AND a OR c AND a

SELECT x FROM (
    SELECT x FROM a
    INTERSECT
    SELECT x FROM (SELECT x FROM b UNION SELECT x FROM c)x
)x ORDER BY x;

SELECT x FROM (
    SELECT x FROM (SELECT x FROM b INTERSECT SELECT x FROM a)x
    UNION
    SELECT x FROM (SELECT x FROM c INTERSECT SELECT x FROM a)x
)x ORDER BY x;


MariaDB [menge001]> SELECT x FROM (
    ->     SELECT x FROM a
    ->     INTERSECT
    ->     SELECT x FROM (SELECT x FROM b UNION SELECT x FROM c)x
    -> )x ORDER BY x;
+------+
| x    |
+------+
| 0    |
| 1    |
| 10   |
| 11   |
| 12   |
| 13   |
| 2    |
| 3    |
| 4    |
| 5    |
| 6    |
| 7    |
| 8    |
+------+
13 rows in set (0.004 sec)

MariaDB [menge001]> SELECT x FROM (
    ->     SELECT x FROM (SELECT x FROM b INTERSECT SELECT x FROM a)x
    ->     UNION
    ->     SELECT x FROM (SELECT x FROM c INTERSECT SELECT x FROM a)x
    -> )x ORDER BY x;
+------+
| x    |
+------+
| 0    |
| 1    |
| 10   |
| 11   |
| 12   |
| 13   |
| 2    |
| 3    |
| 4    |
| 5    |
| 6    |
| 7    |
| 8    |
+------+
13 rows in set (0.005 sec)