SQL Avg Function
SQL Avg Function is used to compute the average records value in a column of specified table.
Understand with Example
The Tutorial illustrate an example from 'SQL Avg Function'. To understand and grasp the example we create a table 'stu' with required fieldnames and datatypes respectively.
Create table:
create table Stu(Id varchar(2), Name varchar(15), Class varchar(10),sub_id varchar(2),marks varchar(3)); |
Insert records into:
The insert into is used to add the records or rows to the table 'Stu'.
insert into Stu values(1,'Komal',10,1,45); insert into Stu values(2,'Ajay',10,1,56); insert into Stu values(3,'Rakesh',10,1,67); insert into Stu values(1,'Komal',10,2,47); insert into Stu values(2,'Ajay',10,2,53); insert into Stu values(3,'Rakesh',10,2,57); insert into Stu values(1,'Komal',10,3,45); insert into Stu values(2,'Ajay',10,3,56); insert into Stu values(3,'Rakesh',10,3,67); insert into Stu values(1,'Komal',10,4,65); insert into Stu values(2,'Ajay',10,4,56); insert into Stu values(1,'Komal',10,5,65); insert into Stu values(3,'Rakesh',10,5,63); |
Stu table:
+------+--------+-------+--------+-------+ | Id | Name | Class | sub_id | marks | +------+--------+-------+--------+-------+ | 1 | Komal | 10 | 1 | 45 | | 2 | Ajay | 10 | 1 | 56 | | 3 | Rakesh | 10 | 1 | 67 | | 1 | Komal | 10 | 2 | 47 | | 2 | Ajay | 10 | 2 | 53 | | 3 | Rakesh | 10 | 2 | 57 | | 1 | Komal | 10 | 3 | 45 | | 2 | Ajay | 10 | 3 | 56 | | 3 | Rakesh | 10 | 3 | 67 | | 1 | Komal | 10 | 4 | 65 | | 2 | Ajay | 10 | 4 | 56 | | 1 | Komal | 10 | 5 | 65 | | 3 | Rakesh | 10 | 5 | 63 | +------+--------+-------+--------+-------+ |
Query:
The Query below uses group by clause that returns you the unique average value of marks from table stu.
select id, name,avg(marks) from stu group by id; |
Result
+------+--------+------------+ | id | name | avg(marks) | +------+--------+------------+ | 1 | Komal | 53.4 | | 2 | Ajay | 55.25 | | 3 | Rakesh | 63.5 | +------+--------+------------+ 3 rows in set (0.00 sec) |