Question

I have a table with Student ID’s and Student Names. There has been issues with assigning unique Student Id’s to students and Hence I want to find the duplicates

Here is the sample Table:

Student ID  Student Name
   1                 Jack
   1                 John
   1                 Bill
   2                 Amanda
   2                 Molly
   3                 Ron
   4                 Matt
   5                 James
   6                 Kathy
   6                 Will

Here I want a third column “Duplicate_Count” to display count of duplicate records.
For e.g. “Duplicate_Count” would display “3” for Student ID = 1 and so on. How can I do this?

Thanks in advance

Answer 1

  Select StudentId, Count(*) DupCount
  From Table
  Group By StudentId
  Having Count(*) > 1
  Order By Count(*) desc,