SQL Row_Count function with Partition

Question

I have a query that returns a set of results as a table called DATA , from several UNION ALL joined queries.

I am then doing ROW_NUMBER() on this, to get the row number for a specific grouping (WorksOrderNo)

ROW_NUMBER() Over(partition by Data.WorksOrderNo order by Data.WorksOrderNo) as RowNo,

Is there an equivalent ROW_Count function where I can specify a partition, and return the count of rows for that partition?

ROW_Count() Over(partition by Data.WorksOrderNo order by Data.WorksOrderNo) as RowNo ???

Reason being, this is query being used to drive a report layout. As part of this, I need to format based on whether the total row count for each WorksOrderNo is >1 or not.

So for instance if there were three rows for a works order, the row_number function currently returns 1, 2 and 3, where the row count would return 3 on each row.

Answer 1

The function is simply COUNT() . In SQL Server, all the aggregation functions can be used as window functions, as long as they do not use DISTINCT .

Note that for the total count, you do not want the ORDER BY :

COUNT(*) Over (partition by Data.WorksOrderNo) as cnt

If you include the ORDER BY , then the COUNT() is cumulative, rather than constant for all rows in the partition.

Answer 2

It looks like you just need group by and count :

select WorksOrderNo, count(*) as Row_Count
from Data 
group by WorksOrderNo