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The screenshot below shows how NULL values look in database. The NOT logical operator is used to test for Boolean conditions and returns true if the condition is false. The NOT operator returns false if the condition been tested is true. There will be cases when we will have to perform computations on a query result set and return the values. Performing any arithmetic operations on columns that have the NULL value returns null results. In order to avoid such situations from happening, we can employ the use of the NOT NULL clause to limit the results on which our data operates.
Zack Macomber Zack Macomber 6, 13 13 gold badges 54 54 silver badges 97 97 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. That threw me for a loop today. Michael Pakhantsov Michael Pakhantsov As all are given answers I want to add little more. I had also faced the same issue. Why did your query fail?
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