How to use ROUND function to intercept decimal places in MySQL

How to use the ROUND function to intercept the number of decimal places in MySQL

In MySQL, you can use the ROUND function to intercept the number of decimal places. The ROUND function rounds a number to a specified number of decimal places. The following will introduce you to the use of ROUND function in detail and provide code examples.

Syntax:
ROUND(X, D)

X represents the number to be rounded, and D represents the number of decimal places to be retained.

Example of using the ROUND function to intercept the number of decimal places:
Suppose there is a table named product that contains the following columns:
id int(11),
name varchar(50),
price decimal(8,2).

Now we want to query the price of this table and round the price to two decimal places.

Code example:
SELECT name, ROUND(price, 2) AS rounded_price
FROM product;

Through the above query statement, we will select the name column and The price column after rounding. We gave the new column an ​​alias rounded_price, which represents the rounded price.

For example, part of the data in the product table is as follows:

id | name | price
1 | TV | 1299.99
2 | Mobile phone | 799.50
3 | Computer | 799.45

After executing the above query statement, the returned results are as follows:

name | rounded_price
TV| 1300.00
Mobile phone| 799.50
Computer| 799.45

As can be seen from the results, the price field is rounded to two decimal places, and the number of digits after the decimal point meets our requirements.

You can also use the ROUND function in combination with other SQL statements to perform more complex calculations and queries. For example, we can calculate the average price of a product:

Code example:
SELECT ROUND(AVG(price), 2) AS average_price
FROM product;

Through the above query statement , we used the ROUND function and the AVG function to calculate the average of product prices, and kept the result to two decimal places.

If our requirement is to directly update the value after retaining decimal places in the database, we can use the UPDATE statement combined with the ROUND function to achieve this.

Code example:
UPDATE product
SET price = ROUND(price, 2);

The above code will update the price column in the product table and change each value Round to two decimal places.

Summary:
In MySQL, the ROUND function can be used to easily intercept the number of decimal places. By combining with other SQL statements, we can perform various complex calculations and query operations. If you need to directly update the value after retaining decimal places in the database, you can use the UPDATE statement combined with the ROUND function to achieve this.

I hope this article can help you understand how to use MySQL's ROUND function to intercept the number of decimal places, as well as related code examples. If you have any questions, please feel free to ask us.

The above is the detailed content of How to use ROUND function to intercept decimal places in MySQL. For more information, please follow other related articles on the PHP Chinese website!