How to Drop a Function in MySQL: Syntax and Examples

To drop a stored function in MySQL, use the DROP FUNCTION function_name; statement. This command removes the function permanently from the database.

Syntax

The syntax to drop a function in MySQL is simple. You write DROP FUNCTION followed by the name of the function you want to remove. This deletes the function from the database.

• DROP FUNCTION: The command to remove a stored function.
• function_name: The exact name of the function you want to delete.

sql

DROP FUNCTION function_name;

Example

This example shows how to drop a function named calculate_tax. After running this command, the function will no longer exist in the database.

sql

DROP FUNCTION calculate_tax;

Output

Query OK, 0 rows affected (0.01 sec)

Common Pitfalls

Some common mistakes when dropping functions include:

• Trying to drop a function that does not exist, which causes an error.
• Not having sufficient privileges to drop the function.
• Confusing functions with procedures; DROP FUNCTION only works for functions.

To avoid errors when the function might not exist, use DROP FUNCTION IF EXISTS function_name;.

sql

/* Wrong: dropping a non-existing function without IF EXISTS */
DROP FUNCTION calculate_tax;

/* Right: safely drop if exists */
DROP FUNCTION IF EXISTS calculate_tax;

Output

ERROR 1305 (42000): FUNCTION calculate_tax does not exist

Query OK, 0 rows affected (0.01 sec)

Quick Reference

Command	Description
DROP FUNCTION function_name;	Deletes the specified function from the database.
DROP FUNCTION IF EXISTS function_name;	Deletes the function only if it exists, avoiding errors.
SHOW FUNCTION STATUS;	Lists all stored functions in the current database.

Key Takeaways

Use DROP FUNCTION function_name; to remove a stored function in MySQL.

Add IF EXISTS to avoid errors if the function does not exist.

Ensure you have the right privileges to drop functions.

DROP FUNCTION only works for functions, not procedures.

Check existing functions with SHOW FUNCTION STATUS before dropping.