Getting a fixed number of rows from various items

Question

Hello,
I am new to Oracle and I am having a hard time resolving this problem. I will try to explain as best as possible.
The application requires that I build a list of items that have been shipped. As they may have various shipping companies, there may be various tracking numbers for each item shipped. The application requires that I get a list of the items that have been shipped that meet certain criteria, then for each item, list the first three tracking numbers that are found. If the shipped item has more than three tracking numbers, the others beyond the third are ignored. I built a SELECT statement using the rownum "column" to limit my result set to a maximum of three. My intention was to build a list of
item ids, then pass those to a stored procedure, then loop for each item id, getting the first three tracking numbers. The tracking numbers returned would be appended to a cursor, which would return the entire set of tracking numbers for the list of item ids.
Any recommendations as to how to approach this requirement would be greatly appreciated. I have gotten through the SELECT that returns the list of item ids. I am having trouble finding the correct approach to getting the three tracking numbers for each item id. One solution was to have the application cycle through each
item id, but I am hoping that this can be done within the stored procedure so that it is called only once for the returned list of item ids.
I wish to thank you in advance. This is all the information I can provide, as I don't have any DDL statements. I hope it will suffice.
Salvador
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Answer 1

Please see if you can use something like this:
SELECT a.item, a.tracking_number
FROM table_name a
WHERE 3 >=
(SELECT COUNT (*) + 1
FROM table_name b
WHERE a.item = b.item
AND b.ROWID < a.ROWID
AND b.criteria = 'whatever')
AND a.criteria = 'whatever'
ORDER BY a.item, a.tracking_number
For example, if you have a table named items_shipped that has columns named item, tracking_num, and shipped, and you want all the items that meet the criteria that shipped = 'Y' and the first three tracking_nums for those items, then your query would look something like this:
SELECT a.item, a.tracking_num
FROM items_shipped a
WHERE 3 >=
(SELECT COUNT (*) + 1
FROM items_shipped b
WHERE a.item = b.item
AND b.ROWID < a.ROWID
AND b.shipped = 'Y')
AND a.shipped = 'Y'
ORDER BY a.item, a.tracking_num
You have given very limited information. If the above suggestions are not sufficient, please provide your table structure, including table names, column names, data types and lengths, some sample data, what criteria must be met, and a sample of what you would like the output to be.
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