I am wondering if there is any difference in regards to performance between the following
SELECT ... FROM ... WHERE someFIELD IN(1,2,3,4)
SELECT ... FROM ..
It depends on what you are doing; how wide is the range, what is the data type (I know your example uses a numeric data type but your question can also apply to a lot of different data types).
This is an instance where you want to write the query both ways; get it working and then use EXPLAIN to figure out the execution differences.
I'm sure there is a concrete answer to this but this is how I would, practically speaking, figure out the answer for my given question.
This might be of some help: http://forge.mysql.com/wiki/Top10SQLPerformanceTips
Regards,
Frank