Controlla 5.1.5 Variabili di sistema del server::controlli_chiavi_estere :
mysql> SELECT @@GLOBAL.foreign_key_checks, @@SESSION.foreign_key_checks;
+-----------------------------+------------------------------+
| @@GLOBAL.foreign_key_checks | @@SESSION.foreign_key_checks |
+-----------------------------+------------------------------+
| 1 | 1 |
+-----------------------------+------------------------------+
1 row in set (0.01 sec)
AGGIORNAMENTO
mysql> SELECT VERSION();
+-----------+
| VERSION() |
+-----------+
| 5.7.18 |
+-----------+
1 row in set (0.00 sec)
mysql> SELECT IF((SELECT `VARIABLE_VALUE`
-> FROM `performance_schema`.`global_variables`
-> WHERE `VARIABLE_NAME` = 'foreign_key_checks') = 'ON', 1, 0) `global.foreign_key_checks`,
-> IF((SELECT `VARIABLE_VALUE`
-> FROM `performance_schema`.`session_variables`
-> WHERE `VARIABLE_NAME` = 'foreign_key_checks') = 'ON', 1, 0) `session.foreign_key_checks`;
+---------------------------+----------------------------+
| global.foreign_key_checks | session.foreign_key_checks |
+---------------------------+----------------------------+
| 1 | 1 |
+---------------------------+----------------------------+
1 row in set (0.00 sec)