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What is Nullif?
The MySQL NULLIF() function is used for the comparison of two expressions. The NULLIF() function returns NULL if both the expressions are equal, else it returns the first expression. The NULLIF() function accepts the expressions as parameter and returns NULL if both of them are equal.
What does Nullif mean in SQL?
SQL Server NULLIF() Function The NULLIF() function returns NULL if two expressions are equal, otherwise it returns the first expression.
What is the difference between Nullif and Isnull?
ISNULL and NULLIF are exactly opposite to each other. ISNULL returns NULL if comparison becomes successful. On the other hand, NULLIF returns not null if comparison becomes successful.
What is Nullif Oracle?
The Oracle/PLSQL NULLIF function compares expr1 and expr2. If expr1 and expr2 are equal, the NULLIF function returns NULL. Otherwise, it returns expr1.
Why is Nullif used?
We often use the NULLIF function when the database contains “special” values such as zero or empty string that we want to handle them as NULL values. This is very useful when we use the aggregate functions such as AVG, MAX, MIN, SUM, and COUNT.
IS NULL in if?
The IS NULL condition is used in SQL to test for a NULL value. It returns TRUE if a NULL value is found, otherwise it returns FALSE. It can be used in a SELECT, INSERT, UPDATE, or DELETE statement.
What is Nullif function?
NULLIF ( expression1 , expression2 ) The NULLIF function returns a NULL value if the arguments are equal; otherwise, it returns the value of the first argument. The arguments must be comparable. The result of using NULLIF(e1,e2) is the same as using the expression: CASE WHEN e1=e2 THEN NULL ELSE e1 END.
IS null function Oracle?
The NVL function allows you to replace null values with a default value. If the value in the first parameter is null, the function returns the value in the second parameter. We know that COL1 in the test table contains null in all rows except the first. Using the NVL function we replace the null values with ‘ZERO’.
Can NVL return null?
The NVL function allows you to replace null values with a default value. If the value in the first parameter is null, the function returns the value in the second parameter. If the first parameter is any value other than null, it is returned unchanged.
When does a NULLIF return a null value?
Syntax: NULLIF ( expression , expression ) Returns a null value if the two specified expressions are equal. NULLIF returns the first expression if the two expressions are not equal. If the expressions are equal, NULLIF returns a null value of the type of the first expression.
Which is an example of a NULLIF in SQL?
NULLIF (Transact-SQL) 1 Syntax 2 Arguments. Is any valid scalar expression. 3 Return Types. Returns the same type as the first expression. 4 Remarks. NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL. 5 Examples. 6 See Also
When to use NULLIF in Azure Data Warehouse?
APPLIES TO: SQL Server Azure SQL Database Azure SQL Data Warehouse Parallel Data Warehouse Returns a null value if the two specified expressions are equal. For example, SELECT NULLIF(4,4) AS Same, NULLIF(5,7) AS Different; returns NULL for the first column (4 and 4) because the two input values are the same.
Is there such thing as null in SQL Server?
Sidenote: In the SQL Server world, I have seen lots of people getting confused with NULL. They think null is nothing, or null is undefined or is null infinite. Actually, none of the answer is true. Null has been just Null. You can’t compare the null with any other value.