layout: global title: DROP FUNCTION displayTitle: DROP FUNCTION license: | Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
The DROP FUNCTION
statement drops a temporary or user defined function (UDF). An exception will be thrown if the function does not exist.
DROP [ TEMPORARY ] FUNCTION [ IF EXISTS ] function_name
function_name
Specifies the name of an existing function. The function name may be optionally qualified with a database name.
Syntax: [ database_name. ] function_name
TEMPORARY
Should be used to delete the TEMPORARY
function.
IF EXISTS
If specified, no exception is thrown when the function does not exist.
-- Create a permanent function `test_avg` CREATE FUNCTION test_avg AS 'org.apache.hadoop.hive.ql.udf.generic.GenericUDAFAverage'; -- List user functions SHOW USER FUNCTIONS; +----------------+ | function| +----------------+ |default.test_avg| +----------------+ -- Create Temporary function `test_avg` CREATE TEMPORARY FUNCTION test_avg AS 'org.apache.hadoop.hive.ql.udf.generic.GenericUDAFAverage'; -- List user functions SHOW USER FUNCTIONS; +----------------+ | function| +----------------+ |default.test_avg| | test_avg| +----------------+ -- Drop Permanent function DROP FUNCTION test_avg; -- Try to drop Permanent function which is not present DROP FUNCTION test_avg; Error: Error running query: org.apache.spark.sql.catalyst.analysis.NoSuchPermanentFunctionException: Function 'default.test_avg' not found in database 'default'; (state=,code=0) -- List the functions after dropping, it should list only temporary function SHOW USER FUNCTIONS; +--------+ |function| +--------+ |test_avg| +--------+ -- Drop Temporary function DROP TEMPORARY FUNCTION IF EXISTS test_avg;