MySQL Aggregate Functions: MAX Function Tutorial

What is the MAX Function?

The MAX function returns the maximum value from a set of values in a specified column.

It can be used with numeric, date, and string data types to find the highest number, latest date, or lexicographically greatest string.

• Syntax: MAX(column_name)
• Ignores NULL values in the column
• Returns a single value representing the maximum

Using MAX with Numeric Data

When applied to numeric columns, MAX returns the largest number.

This is useful for finding the highest sales, scores, or quantities.

Using MAX with Date and String Data

MAX can also be used with date columns to find the most recent date.

For string columns, MAX returns the lexicographically greatest value.

Using MAX with GROUP BY

MAX is often combined with GROUP BY to find the maximum value per group.

For example, finding the highest salary in each department.

Best Practices and Common Mistakes

Using MAX correctly ensures accurate and efficient queries.

• Always specify the correct column or expression inside MAX.
• Remember that MAX ignores NULL values; ensure your data is clean.
• Use GROUP BY when you need maximum values per group.
• Avoid using MAX on columns with mixed data types.