mysql - How do I use MAX() to return the row that has the max value? -

i have table orders fields id, customer_id , amt:

sql fiddle

and want customer_id largest amt , value of amt.

i made query:

select customer_id, max(amt) orders; 

but result of query contained incorrect value of customer_id.

then built such query:

select customer_id, max(amt) maximum orders group customer_id order maximum desc limit 1; 

and got correct result.

but not understand why first query not worked properly. what doing wrong?

and possible change second query obtain necessary information me in simpler , competent way?

mysql allow leave group by off of query, returning max(amt) in entire table arbitrary customer_id. other rdbms require group by clause when using aggregate.

i don't see wrong 2nd query -- there other ways it, yours work fine.