Finding Last Seven Days Data

How to find last seven days data and if any of days data is null then gives null.

This explanation about Oracle SQL Query:

Generally most of the people confuse here is how to handle NULL values.

so, here I am going to show you how we can do this.

I am taking Sales Date  and replacing NVL with SYSDATE means it treats like this is the Max or today date greater than or equal to SYSDATE-7 means seven days back date (ex 2017-11-4 - 7 days: 2017-10-29)

Query:

SELECT * FROM Tbl_Daily_Sales WHERE NVL(Sale_Date,SYSDATE) >= (SYSDATE-7);

Please find below Output:

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