Remove the null columns in query output

 Hello,

How can i remove the null columns in query output like ..

 the data in my table is like this 

col1-----col2------col3-----col4-----col5

a--------null-------1-------null------null

b--------w---------2-------null------null

c--------null-------3--------null------null

d--------x---------null------null------null

e--------y---------4--------null------null

here all the data in col4 and col5 is null so i dont want these columns in output

 ( the data may chnage so in future the columns also change)  

i want to extarct data like this 

col1------col2------col3

a---------null--------1

b---------w---------2

c---------null--------3

d---------x----------null

e---------y----------4

Thanks,

Raj