The count function of SQL
- The SQL Count() function returns the total count of rows for the given column in the table.
- The Count can also return all number of rows if ‘*’ is given in the select count statement.
- If given column contains Null values, it will not be counted.
Syntax of using count
The general syntax of using the count SQL function is:
Select count(column_name) from table_name
Where col_name = value
The Video of this Tutorial
Examples of using count SQL function
Following examples shows how to use SQL select with the count. In our examples, we will use the tbl_emp_salary_paid table that stores the employees salaries.
The data in the table is shown with each example below to make it easier to understand. Simply click the Demo link with each example.
Example of using count in simple select statement
This example returns the total number of records exist in the tbl_emp_salary_paid table by using the count function.
The SQL select with count statement:
select count(*) as Total_records from tbl_emp_salary_paid
Example of using count with Distinct clause
This example returns the total number of unique employee names exist in the emp_name column by using count function with the DISTINCT clause.
The count function distinct clause query:
select count(DISTINCT emp_name) as Total_unique_employees from tbl_emp_salary_paid
Example of using count with Group by clause
This query will return the total number of times salary paid to each employee by using the count aggregate function with the group by clause.
The SQL count with group by statement:
select emp_name,count(emp_sal_paid) as Total_times_paid from tbl_emp_salary_paid
group by emp_name
As you can see in the above graphic, two queries are shown. One with the simple select statement to show all records in the table. The other query uses select with count and group by clause to show the total number of times the salary is paid to each employee.