Issues and questions abotu data>>validation

[taz23340]

Hello all,

I`ve been using the help search files on the mrexcel website to find a solution and don`t seem to find many people with the same issues.

here is my situation

i have four lists of data that i must combine into one.
there are two lists for march and two for june that must all be into one semi annual list.
the main info is the same, such as serial numbers adress and so on.
however there is some data that changes in column g and h.

what i need to is two fold.
first combine the list to not have any duplicates and then the four lists to provide me with the lowest number associated to one serial number in column g and the highest in row h.

ive created a consolidated list using data consolidate and i used the Min function when combining columns f(serial number) and g( a number i need to show the lowest)

why then did i end up with some blank spaces besides some serial numbers?

also can consolidate be used for a large dataset as in 7 or 8 columns?

i was thinking on just creating the single master list of serial numbers and then a vlookup to the four datasheets to bring back min or max, but not sure what formula would work best with the vlookup. would i be better to say if this cell is bigger than this cell use this, but each cell would be a seperate vlookup in each range...would this not be too long?

thanks for the help
and let me know how i can clear things up.