Using MySQL's AVG function to calculate the average value of numeric columns in a data table
Introduction:
MySQL is an open source relational database management system with a wealth of built-in functions for processing and calculations data. Among them, the AVG function is a function used to calculate the average of a numeric column. This article will introduce how to use the AVG function to calculate the average value of numeric columns in a MySQL data table, and provide relevant code examples.
1. Create a sample data table
First, we need to create a sample data table for demonstration. Suppose we have a data table named "students", which contains information such as each student's student ID (student_id) and grade (score). You can use the following code to create this data table:
CREATE TABLE students ( student_id INT PRIMARY KEY, score INT );
2. Insert sample data
Next, we need to insert some sample data into the "students" table. You can use the following code to insert some student performance information:
INSERT INTO students (student_id, score) VALUES (1, 85), (2, 92), (3, 76), (4, 88), (5, 91);
3. Use the AVG function to calculate the average
Now, we have created sample data and inserted some student performance information. Next, we can use the AVG function to calculate the average of these scores. The following is a code example using the AVG function:
SELECT AVG(score) as average_score FROM students;
Running the above code will return a column named "average_score", which contains the average of the student's scores. The results can be output as a table through the following code:
SELECT FORMAT(AVG(score),2) as average_score FROM students;
4. Calculation result description
The above code will return a column named "average_score", which contains the average of student scores and retains Two decimal places. If we run this command, we will get the following results:
+--------------+ | average_score| +--------------+ | 86.40 | +--------------+
Conclusion:
Using MySQL's AVG function can easily calculate the average value of numeric columns in the data table. Through the above code examples, we can see that the AVG function is easy to use and can flexibly handle different data table structures. This is very useful for data statistics and analysis.
In short, using MySQL's AVG function to calculate the average of numeric columns in a data table is very simple and can be completed with just one line of code. I hope that the introduction in this article can help readers better understand and apply the AVG function and improve the efficiency of data processing and calculation.
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