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Create a MySQL function and find the average of values in a column
Let us first create a table −
mysql> create table DemoTable638 (Name varchar(100),Marks int); Query OK, 0 rows affected (0.68 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable638 values('John',67);
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable638 values('John',90);
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable638 values('David',99);
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable638 values('John',60);
Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −
mysql> select *from DemoTable638;
This will produce the following output −
+-------+-------+ | Name | Marks | +-------+-------+ | John | 67 | | John | 90 | | David | 99 | | John | 60 | +-------+-------+ 4 rows in set (0.00 sec)
Following is the query to create a function that returns an average −
mysql> set global log_bin_trust_function_creators=1; Query OK, 0 rows affected (0.28 sec) mysql> DELIMITER // mysql> CREATE FUNCTION getAverageDemo() RETURNS INT BEGIN DECLARE value INT; SELECT AVG(Marks) INTO value from DemoTable638 WHERE Name="John"; RETURN value; END; // Query OK, 0 rows affected (0.35 sec) mysql> DELIMITER ;
Now you can call the function using select statement −
mysql> select getAverageDemo();
This will produce the following output −
+------------------+ | getAverageDemo() | +------------------+ | 72 | +------------------+ 1 row in set (0.01 sec)
Updated on: 02-Jul-2020
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