babefdee1c
### What changes were proposed in this pull request? Standardize sql reference ### Why are the changes needed? To have consistent docs ### Does this PR introduce any user-facing change? Yes ### How was this patch tested? Tested using jykyll build --serve Closes #26721 from huaxingao/spark-30085. Authored-by: Huaxin Gao <huaxing@us.ibm.com> Signed-off-by: Sean Owen <sean.owen@databricks.com>
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| layout | title | displayTitle | license |
|---|---|---|---|
| global | DROP FUNCTION | DROP FUNCTION | 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 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. |
Description
The DROP FUNCTION statement drops a temporary or user defined function (UDF). An exception will
be thrown if the function does not exist.
Syntax
{% highlight sql %} DROP [ TEMPORARY ] FUNCTION [ IF EXISTS ] [ db_name. ] function_name {% endhighlight %}
Parameters
function_name- The name of an existing function.
TEMPORARY- Should be used to delete the `temporary` function.
IF EXISTS- If specified, no exception is thrown when the function does not exist.
Example
{% highlight sql %}
-- 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; +---------+ | Result | +---------+ +---------+
-- 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; +---------+ | Result | +---------+ +---------+ {% endhighlight %}