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How MySQL stored function evaluates if it got NULL value while using the dynamic values from a table?
In such kind of cases when a stored function got NULL values then it will return NULL as the result. It can be understood from the example below in which we have a NULL value in the records of student ‘Mohit’. Now, when we will apply the stored function ‘avg_marks’ on this data, it will return NULL as result.
mysql> Select * from Student_marks; +-------+------+---------+---------+---------+ | Name | Math | English | Science | History | +-------+------+---------+---------+---------+ | Raman | 95 | 89 | 85 | 81 | | Rahul | 90 | 87 | 86 | 81 | | Mohit | 90 | NULL | 86 | 81 | +-------+------+---------+---------+---------+ 3 rows in set (0.00 sec) mysql> SELECT Avg_marks('Mohit') AS 'MOHIT_marks'; +-------------+ | MOHIT_marks | +-------------+ | NULL | +-------------+ 1 row in set (0.00 sec)
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