Igor Micev

Integration specialist, Developer & Programmer, Database administrator, and Architect with 15+ years of
expertise. Experienced in software development, database analysis & design, performance tuning, upgrades &
migrations, high availability solutions implementation, and design, backup and recovery strategies, and system
capacity planning.

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The COUNT Function in T-SQL

The COUNT function is among the most used functions in the T-SQL codes. Even though COUNT is easy to use, it should be used carefully because it could often not return the desired result. For the big tables, the counting of the rows could cause blocking as well as take some more time.

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2018-02-09 (first published: )

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Question of the Day

The Rank Window

I have this table and data:

CREATE TABLE [dbo].[SalesTracking]
(
[SalesDate] [datetime] NULL,
[SalesPersonID] [int] NULL,
[CustomerID] [int] NOT NULL,
[PONumber] [varchar] (80) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
[paid] [bit] NULL,
[total] int
) ON [PRIMARY]
GO
CREATE CLUSTERED INDEX [SalesTrackingCDX] ON [dbo].[SalesTracking] ([SalesDate]) ON [PRIMARY]
GO
INSERT dbo.SalesTracking
  (SalesDate, SalesPersonID, CustomerID, PONumber, paid, total)
VALUES
  ('2024-03-15 10:45:55.067', 1, 1,'PO965' ,1, 100),
  ('2023-09-24 10:45:55.067', 1, 2,'PO627' ,1, 200),
  ('2022-07-02 10:45:55.067', 1, 3,'PO6'   ,1, 300),
  ('2022-11-03 10:45:55.067', 1, 4,'PO283' ,1, 400),
  ('2022-11-26 10:45:55.067', 1, 5,'PO735' ,1, 500),
  ('2023-04-28 10:45:55.067', 1, 6,'PO407' ,1, 600),
  ('2022-09-09 10:45:55.067', 1, 7,'PO484' ,1, 700),
  ('2024-03-13 10:45:55.067', 1, 8,'PO344' ,1, 700),
  ('2024-04-24 10:45:55.067', 1, 9,'PO254' ,1, 800),
  ('2022-06-19 10:45:55.067', 1, 10,'PO344',1, 800)
GO
When I run this query, how many unique values are returned for the SalesRank column?
SELECT
  st.SalesDate
, st.SalesPersonID
, st.total
, RANK () OVER (PARTITION BY st.SalesPersonID
                ORDER BY st.total desc) AS SaleRank
FROM dbo.SalesTracking AS st;

See possible answers