SQL Aggregate Functions Where Clause

SQL Aggregate Functions Where Clause is used to perform various Functions like Sum, Count, Average, Maximum and Minimum.

SQL Aggregate Functions Where Clause

SQL Aggregate Functions Where Clause

     

SQL Aggregate Functions Where Clause is used to perform  various Functions like Sum, Count, Average, Maximum and Minimum.

Understand with Example

The Tutorial illustrate an example  from SQL Aggregate Function Where Clause. To understand and grasp example we create a table 'Stu' that include a required fieldnames and datatypes respectively.

 

 

 

Create Table Stu:

create table Stu(Id varchar(2), Name varchar(15), 
Class  varchar(10),sub_id varchar(2),marks varchar(3));

Insert Data into Stu:

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(3,'Rakesh',10,4,37);
insert into Stu values(1,'Komal',10,5,65);
insert into Stu values(2,'Ajay',10,5,46);
insert into Stu values(3,'Rakesh',10,5,63);

Stu

+--------+----------+-----------+--------+-------+
| 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    |
| 3      | Rakesh   | 10        | 4      | 37    |
| 1      | Komal    | 10        | 5      | 65    |
| 2      | Ajay     | 10        | 5      | 46    |
| 3      | Rakesh   | 10        | 5      | 63    |
+--------+----------+-----------+--------+-------+

Query:

The Query returns you only those columns id, name and sum of the marks that  exists in the name records in where clause from table stu.. 

select id, name, sum(marks) as 'total marks' 
from stu where name in('komal','ajay','santosh','rakesh') group by id;

Result

+------+--------+-------------+
| id   | name   | total marks |
+------+--------+-------------+
| 1    | Komal  | 267         |
| 2    | Ajay   | 267         |
| 3    | Rakesh | 291         |
+------+--------+-------------+