Rank Values by Partition in SQL

I am trying to create a new column that counts unique partitions of another column.

 ColA *NewCol
 ------------
 A    1
 A    1
 A    1
 B    2
 B    2
 C    3
 C    3
 C    3

​x
 
 ColA *NewCol ------------ A    1 A    1 A    1 B    2 B    2 C    3 C    3 C    3​

I have tried using

DENSE_RANK() OVER (PARTITION BY ColA ORDER BY ColA)

 
DENSE_RANK() OVER (PARTITION BY ColA ORDER BY ColA)​

but each partition’s count stays the same at 1.

How would I go about getting results for *NewCol?

Answer

You are looking for just the order by

select dense_rank(*) over (order by cola)

 
select dense_rank(*) over (order by cola)​

The partition by causes the value to be 1 for all cola, because only one value is considered in each partition.