SQL Count function you really need Group By

The Count(*) function is an aggregate function in SQL. You can find Count value from your SQL statement.

SQL Count function important information

Count function you can use as a Column in SELECT statement
You cannot use Count function in Where clause
You can use Count function with Having clause
You can use Group By along with all Aggregate functions.

SQL Count function how to use correctly.
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Count means, the count value of fields you are looking from a Table. In this post , I will compare my results, by running a query.

SQL Count Aggregate function

In this post I am creating a Table and I will insert rows. Then I get data from the Table using Count Function.

If you do not use SQL query correctly, you will not get correct result.

Steps that I followed to use Count function

Step:1 to enter data into a Table

S.NO	Student Name	Country Name
1	Ramani	USA
2	Krishna	Japan
3	Mani	UK
4	Rani	India

Step: 2 To create Table using SQL query

create table counttable(sno integer,
           student_name varchar(20),
             country_name char(20));

Step: 3 SQL query to check Table created or not

desc counttable;

Table “desc” result

sno int(11) YES NULL 
student_name varchar(20) YES NULL 
country_name char(20) YES NULL

Also Read: What is aggregate function by dofactory

Step: 4 SQL Query to Insert values into a Table

insert into counttable values
(1, 'Ramani', 'USA');
insert into counttable values
(
2, 'Krishan', 'Japan'
);
insert into counttable values
(
3, 'Mani', 'UK'
);
insert into counttable values
(
4, 'Rani', 'India'
);

SQL Result after inserting values

1 Ramani USA 
2 Krishan Japan 
3 Mani UK 
4 Rani India

Step: 5 SQL Query “Count function” with Group By and Order By

An SQL query to find a student who studied in USA by using SQL Count Group by

select student_name, count(*)
from counttable
where country_name = 'USA'
group by student_name
order by student_name;

Group By student_name command allows for the Aggregates to be calculated per student_name.

The data has also been sorted with the ORDER BY statement.

Result of SQL Count (*)

Ramani 1

The important point is the non-aggregate field in SELECT statement requires GROUP BY. The ORDER BY will sort the result. If you do not want sort, you no need to use in your SQL.