Parece que ainda não é suportado pelo driver mysql. Fazendo uma verificação rápida por meio da depuração, parece que a seguinte instrução sql é inserida:
SELECT NULL AS PKTABLE_CAT,
A.REFERENCED_TABLE_SCHEMA AS PKTABLE_SCHEM,
A.REFERENCED_TABLE_NAME AS PKTABLE_NAME,
A.REFERENCED_COLUMN_NAME AS PKCOLUMN_NAME,
A.TABLE_CATALOG AS FKTABLE_CAT,
A.TABLE_SCHEMA AS FKTABLE_SCHEM,
A.TABLE_NAME AS FKTABLE_NAME,
A.COLUMN_NAME AS FKCOLUMN_NAME,
A.ORDINAL_POSITION AS KEY_SEQ,
NULL AS UPDATE_RULE,
NULL AS DELETE_RULE,
A.CONSTRAINT_NAME AS FK_NAME,
NULL AS PK_NAME,
NULL AS DEFERABILITY,
NULL AS UNIQUE_OR_PRIMARY
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE A,
INFORMATION_SCHEMA.TABLE_CONSTRAINTS B
WHERE A.TABLE_SCHEMA = B.TABLE_SCHEMA AND A.TABLE_NAME = B.TABLE_NAME
AND A.CONSTRAINT_NAME = B.CONSTRAINT_NAME AND B.CONSTRAINT_TYPE IS NOT NULL
AND A.TABLE_NAME = ? ORDER BY A.TABLE_SCHEMA, A.TABLE_NAME, A.ORDINAL_POSITION
Observe que as colunas UPDATE_RULE e DELETE_RULE estão definidas como NULL.
