How to use the MAX function in MySQL to find the maximum value of a field

How to use the MAX function in MySQL to find the maximum value of a field

In MySQL, we can use the MAX function to find the maximum value of a field. The MAX function is an aggregate function used to find the maximum value of a specified field.

The syntax for using the MAX function is as follows:

SELECT MAX(column_name) FROM table_name;

Among them, column_name is the field name to find the maximum value, and table_name is the query Table Name.

The following uses an example to demonstrate how to use the MAX function to find the maximum value of a field.

Suppose we have a table named students, which has three fields: id, name and score. Now we want to find the maximum value of the score field.

First, we need to create a table named students and insert some data. You can use the following SQL statements to create and insert data:

CREATE TABLE students (

id INT PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(50) NOT NULL,
score INT NOT NULL

);

INSERT INTO students (name, score) VALUES ('Tom' , 80);
INSERT INTO students (name, score) VALUES ('Jerry', 90);
INSERT INTO students (name, score) VALUES ('Alice', 70);
INSERT INTO students (name, score) VALUES ('Bob', 85);

Now, we can use the MAX function to find the maximum value of the score field. You can use the following SQL statement to achieve this:

SELECT MAX(score) FROM students;

After executing the above SQL statement, the maximum value of the score field, which is 90, will be returned.

In addition to simply finding the maximum value, we can also filter in combination with other conditions. For example, if we only want to find the maximum value with a score greater than 80, we can use the following SQL statement:

SELECT MAX(score) FROM students WHERE score > 80;

Execute the above SQL After the statement, the maximum value with a score greater than 80, which is 85, will be returned.

In addition, we can also use the DISTINCT keyword in the MAX function to find the unique maximum value. For example, if we have some duplicate scores and we just want to find the unique highest score, we can use the following SQL statement:

SELECT MAX(DISTINCT score) FROM students;

Execute After the above SQL statement, the only maximum value of the score field, which is 90, will be returned.

To sum up, using the MAX function you can easily find the maximum value of a certain field. We can filter based on other conditions as needed, or use the DISTINCT keyword to find the unique maximum value. Using the MAX function can simplify our query operations and improve the efficiency of data processing.

I hope this article can help readers better understand and use the MAX function in MySQL.

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