How to Use the MySQL ROUND() Function
In this tutorial, we'll learn how to use the MySQL ROUND() function. ROUND() is a function to round a number to a specified number of decimal paces.
MySQL ROUND() Syntax
The syntax of the ROUND() function is as follows:
ROUND(number, digits)
or
ROUND(number)
Remarks
- The number argument is required.
- The digits argument is optional and defaults to 0 if not specified. It can be positive or negative number.
Examples
Example 1: Round a Number to 2 Decimal Places
The following statement rounds the number to 2 decimal places:
SELECT ROUND(2000.4598, 2);
Result:
2000.46
Example 2: Round a Number to 0 Decimal Places
The following statement rounds the number to 0 decimal places:
SELECT ROUND(2000.4598);
or:
SELECT ROUND(2000.4598, 0);
Result:
2000
Example 3: Round a Number to -1 Decimal Places
The following statement rounds the number to -1 decimal places:
SELECT ROUND(25.298, -1);
Result:
30
Example 4: Round a Number to -1 Decimal Places
The following statement rounds the number to -1 decimal places:
SELECT ROUND(24.298, -1);
Result:
20
Example 5: Round a Number to -2 Decimal Places
The following statement rounds the number to -2 decimal places:
SELECT ROUND(25.298, -2);
Result:
0
Example 6: Round a Number to 3 Decimal Places
The following the number to 3 decimal places:
SELECT ROUND(20.29, 3);
Result:
The rounded value is 20.29, which is the same as the number since the number has 2 decimal places but we're trying to round it to 3 decimal places.
Example 7: ROUND(), SUM() and COUNT()
The following statement rounds the number, calculated by SUM() / COUNT() in the orders table, to 2 decimal places:
SELECT ROUND((SUM(o.amount) / COUNT(o.order_id)), 2)
FROM orders o;
Result:
For example, if the result returned from SUM() / COUNT() is 1988.775000, then rounded value is 1988.78.
In this tutorial, we've learned how to use the MySQL ROUND() function. The ROUND() function is used to round a number to a specified number of decimal places. The number of decimal places can be positive or negative.