layout: global title: SHOW FUNCTIONS displayTitle: SHOW FUNCTIONS 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
Returns the list of functions after applying an optional regex pattern. Given number of functions supported by Spark is quite large, this statement in conjunction with describe function may be used to quickly find the function and understand its usage. The LIKE
clause is optional and supported only for compatibility with other systems.
SHOW [ function_kind ] FUNCTIONS [ [ LIKE ] { function_name | regex_pattern } ]
function_kind
Specifies the name space of the function to be searched upon. The valid name spaces are :
function_name
Specifies a name of an existing function in the system. The function name may be optionally qualified with a database name. If function_name
is qualified with a database then the function is resolved from the user specified database, otherwise it is resolved from the current database.
Syntax: [ database_name. ] function_name
regex_pattern
Specifies a regular expression pattern that is used to filter the results of the statement.
*
and |
character, the pattern works like a regular expression.*
alone matches 0 or more characters and |
is used to separate multiple different regular expressions, any of which can match.-- List a system function `trim` by searching both user defined and system -- defined functions. SHOW FUNCTIONS trim; +--------+ |function| +--------+ | trim| +--------+ -- List a system function `concat` by searching system defined functions. SHOW SYSTEM FUNCTIONS concat; +--------+ |function| +--------+ | concat| +--------+ -- List a qualified function `max` from database `salesdb`. SHOW SYSTEM FUNCTIONS salesdb.max; +--------+ |function| +--------+ | max| +--------+ -- List all functions starting with `t` SHOW FUNCTIONS LIKE 't*'; +-----------------+ | function| +-----------------+ | tan| | tanh| | timestamp| | tinyint| | to_csv| | to_date| | to_json| | to_timestamp| |to_unix_timestamp| | to_utc_timestamp| | transform| | transform_keys| | transform_values| | translate| | trim| | trunc| | typeof| +-----------------+ -- List all functions starting with `yea` or `windo` SHOW FUNCTIONS LIKE 'yea*|windo*'; +--------+ |function| +--------+ | window| | year| +--------+ -- Use normal regex pattern to list function names that has 4 characters -- with `t` as the starting character. SHOW FUNCTIONS LIKE 't[a-z][a-z][a-z]'; +--------+ |function| +--------+ | tanh| | trim| +--------+