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This article mainly introduces how to take the top three in each group from Oracle, which has a certain reference value. Interested friends can refer to it. I hope you will gain a lot after reading this article. Let's take a look at it.

Oracle implements this using window functions and subqueries, which are not easy to write, as follows

SELECT *

FROM (

SELECT g, ROW_NUMBER () OVER (PARTITION BY g

ORDER BY x) group_id RN FROM A

)

WHERE group_id

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