Sql null value nvl

Table of Contents. Improve Article. Save Article. Like Article. Attention reader! Recommended Articles. Article Contributed By :. Easy Normal Medium Hard Expert. DECODE is a comparison feature that allows you to compare a base value of up to evaluation values in a single call. If the base value does not equal any of the evaluation values, a default value can be passed at the end of the function to be returned.

The function returns null if they are equal. The function returns the first expression if they are not identical. For the first word, you can't use the literal NULL. If the input value n1 is NaN, it instructs the database to return an alternative value n2 not a number. Database returns n1 if n1 is not NaN. If the input value n1 is NaN, it instructs the Database to return an alternative value n2 not a number.

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Learn more. Asked 5 years, 2 months ago. Active 5 years, 2 months ago. Viewed 2k times. How can I get the desired output. Jacob Jacob You are comparing productloc with productloc from the same table.. If you remove the where statement you will get all rows.. Keep nvl both sides. NVL '', productloc returns always productloc as '' is equal to null in Oracle — Kacper.

Please share expected final results. Add a comment. If e1 evaluates to non-null, the NVL function returns e1. The two arguments e1 and e2 can have the same or different data types. If their data types are different, Oracle implicit converts one to the other according to the following rules:.

See the following orders and employees tables from the sample database :.