计算列SQL Server中的相同值

Question

I am trying to count Same values in a column and want it to return a count there off.

| ITEM  | COUNT |
+-------+-------+
| GREEN |  1    |
| GREEN |  2    |
| GREEN |  3    |
| RED   |  1    |
| RED   |  2    |

I tried

ROW_NUMBER() OVER (ORDER BY ITEM) AS Row

But that only counts each line 1 - 1000

How would I accomplish this?

Answer 1

Try:

 ROW_NUMBER() OVER (PARTITION BY ITEM ORDER BY ITEM) AS Row

or

 ROW_NUMBER() OVER (PARTITION BY ITEM ORDER BY COUNT) AS Row

You can have count of each ITEM like this:

COUNT(*) OVER (PARTITION BY ITEM) As CountByItem

Answer 2

You'll want to include a partition by clause with the row_number function. This makes the row_number restart from 1 for each new type of item.

ROW_NUMBER() OVER (PARTITION BY ITEM ORDER BY ITEM) AS Row

this would give you a result like:

item    Row
GREEN   1
GREEN   2
GREEN   3
RED     1
RED     2

Answer 3

This code will count same values in table

SELECT item, COUNT(*)
FROM Table
Group by item