SQL MAX

What is SQL MAX?

The SQL MAX function is an aggregate function used to retrieve the maximum (highest) value from a specified column in a database table. It allows you to find the largest value within a column, which is particularly useful for identifying the maximum value in numerical or date-related data.

When you would use it

You would use the SQL MAX function when you need to determine the maximum value in a specific column. This can be valuable in various scenarios, such as finding the latest date, the highest price, or the maximum value of any numeric field in your data.

Syntax

The syntax for using the MAX function is as follows:

SELECT MAX(column_name) FROM table_name WHERE condition;

• column_name: The name of the column for which you want to find the maximum value.
• table_name: The name of the table containing the data.
• condition (optional): An optional condition to filter the rows for which you want to find the maximum.

Parameter values

• column_name: The name of the column in the specified table for which you want to determine the maximum value.
• table_name: The name of the table where the data is stored.
• condition (optional): A condition that filters the rows if you want to apply additional filtering before finding the maximum.

Example query

Suppose we have a table named "product_prices" with columns "product_id" and "price." We want to find the maximum price among all products:

SELECT MAX(price)
FROM product_prices
-- Comment the line below to show it doesn't affect the query.
-- WHERE category = 'Electronics';

In the above query, we use the MAX function to find the maximum price among all products in the "product_prices" table.

Example table response

Assuming the "product_prices" table contains the following data:

| product_id | price   |
|------------|-------- |
| 1         | 99.99   |
| 2         | 149.95  |
| 3         | 79.99   |
| 4         | 199.99  |

The query mentioned earlier would return the following result:

| MAX(price)  |
|------------ |
| 199.99     |

This represents the maximum price among all products in the "product_prices" table.

Use cases

• Finding the highest price for a product.
• Identifying the latest date in a dataset.
• Determining the maximum value within a numeric column, such as the maximum score in a test result table.

SQL languages this is available for

The SQL MAX function is a standard SQL feature and is available in most relational database management systems (RDBMS) that support SQL. This includes popular RDBMS like MySQL, PostgreSQL, Oracle, SQL Server, and SQLite. The specific syntax and behavior may vary slightly between database systems, but the fundamental functionality remains the same.