Error Code: 1005 — there is a wrong primary key reference in your code
Usually it’s due to a referenced foreign key field that does not exist. It might be you have a typo mistake, or check case it should be same, or there’s a field-type mismatch. Foreign key-linked fields must match definitions exactly.
Some known causes may be:
- The two key fields type and/or size doesn’t match exactly. For example, if one is
INT(10)
the key field needs to beINT
as well and notBIGINT
orSMALLINT
orTINYINT
. You should also check that one is notSIGNED
and the other isUNSIGNED
. They both need to be exactly the same. - One of the key field that you are trying to reference does not have an index and/or is not a primary key. If one of the fields in the relationship is not a primary key, you must create an index for that field.
- The foreign key name is a duplicate of an already existing key. Check that the name of your foreign key is unique within your database. Just add a few random characters to the end of your key name to test for this.
- One or both of your tables is a
MyISAM
table. In order to use foreign keys, the tables must both beInnoDB
. (Actually, if both tables areMyISAM
then you won’t get an error message – it just won’t create the key.) In Query Browser, you can specify the table type. - You have specified a cascade
ON
DELETE
SET
NULL
, but the relevant key field is set toNOT
NULL
. You can fix this by either changing your cascade or setting the field to allowNULL
values. - Make sure that the Charset and Collate options are the same both at the table level as well as individual field level for the key columns.
- You have a default value (that is, default=0) on your foreign key column
- One of the fields in the relationship is part of a combination (composite) key and does not have its own individual index. Even though the field has an index as part of the composite key, you must create a separate index for only that key field in order to use it in a constraint.
- You have a syntax error in your
ALTER
statement or you have mistyped one of the field names in the relationship - The name of your foreign key exceeds the maximum length of 64 characters.
For more details, refer to: MySQL Error Number 1005 Can’t create table