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# How to use Count() in SQL

Eman Kashif

SQL (Structured Query Language) provides a range of mathematical functions that can be used to summarize data efficiently.

The COUNT() function returns the number of rows that match a requirement specified in the query.

### Syntax

SELECT COUNT(columnName)
FROM tableName
WHERE condition;

### Code

Let’s create a demo table called Student.

CREATE TABLE Student (
s_ID int,
s_name varchar(255),
s_major varchar(255),
s_age int
);

INSERT INTO Student

INSERT INTO Student
VALUES (93742,'Allie','Econ',17);

INSERT INTO Student
VALUES (31289,'Sally','CS',18);

INSERT INTO Student
VALUES (21328,'Chris','Psych', 20);

INSERT INTO Student
VALUES (32891,'Betty','Arch', 19);

#### Demo table Student

 s_ID s_name s_major s_age 78391 Brad CS 20 93742 Allie Econ 17 31289 Sally CS 18 21328 Chris Psych 20 32891 Betty Arch 19

#### Explanation

We can use the COUNT() function to get the total number of students without going through the entire database ourselves.

This returns the total number of rows in the Student table.

SELECT COUNT(*) As "Number of Students"
FROM Student;

#### COUNT() with WHERE clause

The WHERE clause is added with the function to get rows that fulfill a specific condition.

For example, if we wish to see the number of students above 18, we use the COUNT() function and specify the condition as above 18 in the WHERE clause.

SELECT COUNT(*) As "Students above 18"
FROM Student
WHERE s_age > 18;

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count()
communitycreator

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Eman Kashif
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