MySQL MAX() function

MAX() function

MySQL MAX() function returns the maximum value of an expression.

This function is useful in -

• To identify the highest value within a column is crucial for understanding the upper limit of a dataset.
• When analyzing data, you might want to know the highest or peak value in a certain attribute.
• The MAX() function helps evaluate the highest performance metrics, such as maximum revenue, profits, or user engagement.
• Identifying the maximum value helps in assessing whether a process is operating within acceptable limits.
• When comparing performance against benchmarks, the MAX() function assists in determining how close or far data is from the best achieved results.
• In e-commerce or inventory management, determining the maximum order quantity helps in fulfilling customer demands efficiently.
• For critical decisions, knowing the maximum value in relevant data attributes can provide insights for strategic planning.

Syntax:

MAX(expr);

Where expr is an expression.

MySQL Version: 8.0

Example:

Sample table: book_mast

Code:

-- This SQL query retrieves the maximum value of the book price from the book_mast table.
SELECT MAX(book_price) -- Selects the maximum value of the book price
FROM book_mast; -- Specifies the table from which to retrieve data (book_mast table)

Explanation:

• This SQL query retrieves data from the book_mast table.


• It selects the maximum value of the book price.


• Here's how the process works:


• The query uses the MAX() function to find the maximum value of the book price column.


• It retrieves this value from the book_mast table.


• Finally, the query returns the maximum value of the book price.

Relational Algebra Expression:

Relational Algebra Tree:

Explanation:

The above MySQL statement will return the maximum 'book_price' from 'book_mast' table.

Output:

mysql> SELECT MAX(book_price)
    -> FROM book_mast;
+-----------------+
| MAX(book_price) |
+-----------------+
|          250.00 | 
+-----------------+
1 row in set (0.00 sec)

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