SQL Joins . One to many relationship

Question

I have two tables as below

Table 1
-----------------------------------
UserID   | UserName | Age | Salary
-----------------------------------
1        | foo      | 22  | 33000       
-----------------------------------

Table 2
------------------------------------------------
UserID   | Age      | Salary     | CreatedDate
------------------------------------------------
1        | NULL     | 35000      | 2015-01-01
------------------------------------------------
1        |  28      | NULL       | 2015-02-01
------------------------------------------------
1        |  NULL    | 28000      | 2015-03-01
------------------------------------------------

I need the result like this.

Result
-----------------------------------
UserID   | UserName | Age | Salary
-----------------------------------
1        | foo      | 28  | 28000
-----------------------------------

This is just an example. In my real project I have around 6 columns like Age and Salary in above tables.

In table 2 , each record will have only have one value i.e if Age has value then Salary will be NULL and viceversa.

UPDATE :

Table 2 has CreatedDate Column. So i want to get latest "NOTNULL" CELL Value instead of maximum value.

Answer 1

You can get this done using a simple MAX() and GROUP BY:

select t1.userid,t1.username, MAX(t2.Age) as Age, MAX(t2.Salary) as Salary
from table1 t1 join
     table2 t2 on t1.userid=t2.userid
group by t1.userid,t1.username

Result:

userid  username    Age   Salary
--------------------------------
1       foo         28    35000

Sample result in SQL Fiddle