MySql的自動忽略上表創建

Question

mysql> create database test; 
Query OK, 1 row affected (0.01 sec) 

mysql> use test; 
Database changed 
mysql> create table one (id int not null primary key); 
Query OK, 0 rows affected (0.03 sec) 

mysql> -- here is the problem 
mysql> create table two (oneid int not null references one(id)); 
Query OK, 0 rows affected (0.02 sec) 

mysql> -- here are the first signs of issues!!!! 
mysql> show create table two; 
+-------+----------------------------------------------------------------------------------------+ 
| Table | Create Table                   | 
+-------+----------------------------------------------------------------------------------------+ 
| two | CREATE TABLE `two` (
    `oneid` int(11) NOT NULL 
) ENGINE=InnoDB DEFAULT CHARSET=latin1 | 
+-------+----------------------------------------------------------------------------------------+ 
1 row in set (0.00 sec) 

mysql> -- here is the issue: an insert with no reference 
mysql> insert into two values (-12); 
Query OK, 1 row affected (0.01 sec) 

mysql> select * from two; 
+-------+ 
| oneid | 
+-------+ 
| -12 | 
+-------+ 
1 row in set (0.00 sec) 
mysql> -- if you want to know: 
mysql> SHOW Variables WHERE Variable_name='foreign_key_checks'; 
+--------------------+-------+ 
| Variable_name  | Value | 
+--------------------+-------+ 
| foreign_key_checks | ON | 
+--------------------+-------+ 
1 row in set (0.00 sec) 

「引用」關鍵字我的研究後，這裏唯一的問題是：爲什麼MySQL的不拒絕表二次創作，因爲它無效語法的，而是它靜靜地創建該表外鍵引用？
爲了完整起見，這裏是MySql的正確語法。

mysql> create table three(oneid int not null, CONSTRAINT whatEverName FOREIGN KEY (oneid) REFERENCES one(id)); 
Query OK, 0 rows affected (0.04 sec) 

Answer 1

MySQL的解析，但忽略「內聯參考Specifications」（如在SQL標準中定義的），其中的參考文獻中被定義爲列說明書的一部分。只有在指定爲單獨的FOREIGN KEY規範的一部分時，MySQL才接受REFERENCES子句。

你可以去here多看看自己......