MySQL Bugs: #26304: Inconsistently processed REFERENCES in column and in separate FK def

Bug #26304	Inconsistently processed REFERENCES in column and in separate FK def
Submitted:	13 Feb 2007 0:06	Modified:	13 Feb 2007 0:26
Reporter:	Alex Rytov	Email Updates:
Status:	Duplicate	Impact on me:	None
Category:	MySQL Server: Parser	Severity:	S3 (Non-critical)
Version:	5.1.15	OS:
Assigned to:		CPU Architecture:	Any
Tags:	foreign key, references

Description:
In a table definition, a REFERENCES clause after a column is supposed to be exactly equivalent to a separate FOREIGN KEY definition.  However, in mySQL the former is ignored, while the latter does make an FK (on a suitable storage engine).  

Is this behaviour by design or is it a bug?  If this distinction is on purpose, please consider this report a feature request to make both the column-level REFERENCES and the FK-level one work the same way.

How to repeat:
Consider the following two tables:

create table t(
  i int not null key,
  j int references t(i)
) engine innodb;

and then:

create table t1(
  i int not null key,
  j int,
  foreign key (j) references t1(i)
) engine innodb;

now see what happens:

SELECT * FROM information_schema.TABLE_CONSTRAINTS T;

table T will only have a PK, while T1 has both the PK and the self-referencing FK.

this is a duplicate of http://bugs.mysql.com/bug.php?id=17943

Thank you for your bug report! An identical bug has already been reported and filed as bug #17943