hi all,

I want to know how to select with a condition only on month and year. For example, the total cost on December 2004?

select sum(cost)
from visit
where v_date = "2003-12"; Is this correct?


Thank you very much.

you can take one of two approaches

the simple approach --

... where month(v_date) = 12 and year(v_date) = 2003

the efficient approach --

... where v_date between '2003-12-01' and '2003-12-31'

the second is preferred because it allows the database to utilize an index on v_date