Commands
DROP FUNCTION
Use the DROP FUNCTION
command to remove an existing user-defined function (UDF).
Syntax
Parameter or clause | Description |
---|---|
function_name | Name of the UDF you want to drop. |
( argument_type [ , … ] ) | Optional: Argument types of the function.Specify the argument types when the name of the function you want to drop isn’t unique within the schema. |
IF EXISTS | Do not return an error if the specified function does not exist. A notice is issued in this case. |
Usage
A function can be dropped using one of the following methods:
- Full function signature:
- Function name only, if it’s unique in its schema:
You can run SHOW FUNCTIONS; to list all existing UDFs to see if a function name is unique.
TIP
DROP FUNCTION function_name();
drops a function with zero arguments.
DROP FUNCTION function_name;
drops a function with any number of arguments, including zero, as long as the name is unique.
Examples
First, let’s create some functions.
You can drop a unique function by name:
You cannot drop a function by name when its name is not unique:
You can drop a function by full signature:
Now, f1(int,int)
is the only function named f1
, you can drop it by name or full signature:
See also
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