Question

I haven’t had to work with SQL queries in quite a while and what seems like a simple query is driving me insane. I have a table of transactions from which I am trying to select repetition based on various criteria. The relevant table structure is as follows:

[Transaction]
* ID          int
  Transacted  datetime
  Name        nvarchar(50)
  Description nvarchar(4000)
  size        bigint

From this table, I need to find duplicates of the name / size and report back all records where the name had the same size transaction, even if date and description differ. I can get counts with just the name with the following:

SELECT   Name, COUNT(Name) AS Count
FROM     Transaction
GROUP BY Name

And then I could do an inner join on that to get the rest of the data:

SELECT data.ID, data.Transacted, data.Name, data.Description, data.Size, counts.Count
FROM (SELECT  Name, COUNT(Name) AS Count
      FROM  Transaction
      GROUP BY Name) AS counts 
INNER JOIN Transaction AS data ON counts.Name = data.Name
WHERE     (counts.Count > 1)
ORDER BY  data.Name, data.Transacted

But obviously this is only giving me transactions where the name is repeated — not where both the name and size are repeated.

I’m looking for help finishing this piece off so that I report all of the data where the lines show a repeat of the same name and same size. I could easily concatinate the data from both columns into one result and compare against that, but I’m not sure that’s the optimal appropach.

Thanks in advance.

Answer 1

The code in the question indicates that you also need additional columns. To return all rows with duplicated Name, size you can use

WITH CTE
     AS (SELECT *,
                COUNT(*) OVER (PARTITION BY Name, size) AS Cnt
         FROM   [Transaction])
SELECT ID,
       Transacted,
       Name,
       Description,
       size
FROM   CTE
WHERE  Cnt > 1