根据当前和上一个记录值更新字段/列

Question

I need assistance with updating a field/column "IsLatest" based on the comparison between the current and previous record. I'm using CTE's syntax and I'm able to get the current and previous record but I'm unable updated field/column "IsLatest" which I need based on the field/column "Value" of the current and previous record.

Example

Current Output

Dates                   Customer    Value   IsLatest
2010-01-01 00:00:00.000    1            12  1

Dates                   Customer    Value   IsLatest
2010-01-01 00:00:00.000    1            12  0
2010-01-02 00:00:00.000    1            30  1

Dates                   Customer    Value   IsLatest
2010-01-01 00:00:00.000    1            12  0
2010-01-02 00:00:00.000    1            30  0
2010-01-03 00:00:00.000    1            13  1

Expected Final Output

Dates                   Customer    Value   ValueSetId IsLatest
2010-01-01 00:00:00.000    1            12     12          0
2010-01-01 00:00:00.000    1            12     13          0
2010-01-01 00:00:00.000    1            12     14          0

2010-01-02 00:00:00.000    1            30     12          0
2010-01-02 00:00:00.000    1            30     13          0
2010-01-02 00:00:00.000    1            30     14          0

2010-01-03 00:00:00.000    1            13     12          0
2010-01-03 00:00:00.000    1            13     13          0
2010-01-03 00:00:00.000    1            13     14          0

2010-01-04 00:00:00.000    1            14     12          0
2010-01-04 00:00:00.000    1            14     13          0
2010-01-04 00:00:00.000    1            14     14          1

Answer 1

;WITH a AS
(
SELECT 
  Dates Customer Value, 
  row_number() over (partition by customer order by Dates desc, ValueSetId desc) rn
FROM @Customers)
SELECT Dates, Customer, Value, case when RN = 1 then 1 else 0 end IsLatest
FROM a