Question

I have a master table
containing 8 columns and I want to select unique
combinations of 5 columns.how can i do that in sqlserver?

EDIT:i need to retrieve all 8 columns that have 5 unique columns.

Answer 1

select distinct col1, col2, col3, col4, col5
from YourTable

This can also be achieved by doing:

select col1, col2, col3, col4, col5
from YourTable
group by col1, col2, col3, col4, col5

EDIT: To retrieve all 8 columns with 5 unique, you need to decide how to aggregate those 3 columns. In other words, something like this:

select col1, col2, col3, col4, col5, max(col6), min(col7), sum(col8)
from YourTable
group by col1, col2, col3, col4, col5

In other words, if you aren’t grouping by a particular column you logically need to decide how you want to retrieve the other columns. See this MSDN reference on Aggregate Functions to find all of the possible functions that you can use for aggregation.