USE INFORMATION_SCHEMA;
SELECT
TABLES.table_name
FROM TABLES
LEFT JOIN KEY_COLUMN_USAGE AS c
ON (
TABLES.TABLE_NAME = c.TABLE_NAME
AND c.CONSTRAINT_SCHEMA = TABLES.TABLE_SCHEMA
AND c.constraint_name = 'PRIMARY'
)
WHERE
TABLES.table_schema != 'infomation_schema'
AND c.constraint_name IS NULL;