how to get the unique records with min and max for each user

Question

I have the following table:

id  gender  age highest weight  lowest weight   abc
a   f       30  90              70              1.3
a   f       30  90              65              null
a   f       30  null            null            1.3
b   m       40  100             86              2.5
b   m       40  null            80              2.5
c   f       50  105             95              6.4

I need this result in sql server . What I need is the minimum of the weight and maximum of the weight and one record per user.

id  gender  age highest weight  lowest weight   abc
a   f       30  90              65              1.3
b   m       40  100             80              2.5
c   f       50  105             95              6.4

Answer 1

Just do a grouping:

select id, 
       max(gender), 
       max(age), 
       max([highest weight]), 
       min([lowest weight]), 
       max(abc)
from SomeTable
group by id

Answer 2

You can do this using grouping:

select id, gender, max(highest_weight), min(lowwest_weight) from student
group by id, gender

But you need do define the rule for the other fields with variable value, like abc

Can you post more information?