问题
I'm trying to create a fk but MySQL doesn't allow it ...
Identifier name 'foobarbaz_FK_CATALOG_PRODUCT_ENTITY_WEEE_DISCOUNT_PRODUCT_ENTITY' is too long [ CREATE TABLE `foobarbaz_weee_discount` ( `entity_id` int(10) unsigned NOT NULL DEFAULT '0', `website_id` smallint(5) unsigned NOT NULL DEFAULT '0', `customer_group_id` smallint(5) unsigned NOT NULL, `value` decimal(12,4) NOT NULL DEFAULT '0.0000', KEY `foobarbaz_FK_CATALOG_PRODUCT_ENTITY_WEEE_DISCOUNT_WEBSITE` (`website_id`), KEY `foobarbaz_FK_CATALOG_PRODUCT_ENTITY_WEEE_DISCOUNT_PRODUCT_ENTITY` (`entity_id`), KEY `foobarbaz_FK_CATALOG_PRODUCT_ENTITY_WEEE_DISCOUNT_GROUP` (`customer_group_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; ]
Is there a way to add big fks? Thank you.
回答1:
No, it's hard coded into MySQL, see the docs (towards the bottom of the page). But it has nothing to do with the name of the FK. It's the name of the index that's too long (64 characters max):
`Identifier` `Maximum Length (characters)`
Database 64
Table 64
Column 64
Index 64
Constraint 64
Stored Procedure or Function 64
Trigger 64
View 64
Alias 256 (see exception following table)
Compound Statement Label 16
回答2:
I doubt it. You can try to change the datatype of the system table for foreign keys. However I never tried to change system tables before so no idea if there will be any complications if it is even possible.
回答3:
The foreign key is not the problem. It's the name of the key. I agree with MySQL, 'foobarbaz_FK_CATALOG_PRODUCT_ENTITY_WEEE_DISCOUNT_PRODUCT_ENTITY' is a bit silly :)
You have "PRODUCT_ENTITY" twice in the name. Start by dropping that :)
回答4:
It looks like this may be a bug. Here is the report that I found. I didn't see that it was patched yet but you can just rename your keys so that then length is shorter.
http://bugs.mysql.com/bug.php?id=13942
来源：https://stackoverflow.com/questions/4464714/mysql-big-fk-identifier