How to find latest inserted rows

[g.raaja]

Hi,

I am having a table where same barcodes will be inserted for a project repetetively. My problem is I want to retrieve all the barcodes for that project which are inserted latest and these barcodes are might be previously allocated or new ones or both.

Searched google but found there is no function or predefined variable like rownum in mysql. The queries available in all the forums are using desc and limit but I cant use them as I dont know how many barcodes will be inserted for a particular project again they might be same or more or less in this case I cant use limit.

If my table is having the following records:

barcode insertdate projectid
10009 2011-04-29 1
10037 2011-05-01 1
10444 2011-05-02 1
10019 2011-04-30 2
10047 2011-05-03 2
10464 2011-05-05 3
10009 2011-05-05 1
10037 2011-05-07 1
10464 2011-05-07 1
10444 2011-05-07 1

I want to retrieve all the records of project 1 inserted for the second time only.

Pls help me in getting the result.

--Regards,
raaja. g

[doWhile]

If you are entering the dates, just select the project id and the max date

[Tolls]

If my table is having the following records:

barcode insertdate projectid
10009 2011-04-29 1
10037 2011-05-01 1
10444 2011-05-02 1
10019 2011-04-30 2
10047 2011-05-03 2
10464 2011-05-05 3
10009 2011-05-05 1
10037 2011-05-07 1
10464 2011-05-07 1
10444 2011-05-07 1

I want to retrieve all the records of project 1 inserted for the second time only.

Pls help me in getting the result.

--Regards,
raaja. g

OK, so does that mean you would expect back only the rows for project 1 with duplicate barcodes, and the latest date?
So barcode 10464 will not be returned because there is only the one row?

[g.raaja]

Hi,

But I need all the records which are inserted latest for project 1. I dont want only the duplicates.

--regards,
raaja. g

[g.raaja]

Hi,

What I need is last entry of all the barcodes of a particular project.

--raaja. g

[Tolls]

Right.
I needed to clarify that.
If the above is representative of your table:
SELECT barcode, project_id, max(insert_date)
FROM <your_table>
GROUP BY barcode, project_id

If the rows have additional data that you want and you want the actual rows, then you'll have to use that as a subquery.