MySQL: Determine Table's Primary Key Dynamically

Question

I\'m, generating a SQL query like this in PHP:

$sql = sprintf(\"UPDATE %s SET %s = %s WHERE %s = %s\", ...);

Since almost every part of thi

Answer 1

It might be not advised but works just fine:

SHOW INDEX FROM  WHERE Key_name = 'PRIMARY';

The solid way is to use information_schema:

SELECT k.COLUMN_NAME
FROM information_schema.table_constraints t
LEFT JOIN information_schema.key_column_usage k
USING(constraint_name,table_schema,table_name)
WHERE t.constraint_type='PRIMARY KEY'
    AND t.table_schema=DATABASE()
    AND t.table_name='owalog';

As presented on the mysql-list. However its a few times slower from the first solution.