檢查當前FOREIGN_KEY_CHECKS值

Question

如何檢查FOREIGN_KEY_CHECKS的當前值是什麼？

我想肯定的是，值爲1

Answer 1

檢查5.1.5 Server System Variables::foreign_key_checks：

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) 

UPDATE

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)