layout: global title: LATERAL VIEW Clause displayTitle: LATERAL VIEW Clause 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 LATERAL VIEW
clause is used in conjunction with generator functions such as EXPLODE
, which will generate a virtual table containing one or more rows. LATERAL VIEW
will apply the rows to each original output row.
LATERAL VIEW [ OUTER ] generator_function ( expression [ , ... ] ) [ table_alias ] AS column_alias [ , ... ]
OUTER
If OUTER
specified, returns null if an input array/map is empty or null.
generator_function
Specifies a generator function (EXPLODE, INLINE, etc.).
table_alias
The alias for generator_function
, which is optional.
column_alias
Lists the column aliases of generator_function
, which may be used in output rows. We may have multiple aliases if generator_function
have multiple output columns.
CREATE TABLE person (id INT, name STRING, age INT, class INT, address STRING); INSERT INTO person VALUES (100, 'John', 30, 1, 'Street 1'), (200, 'Mary', NULL, 1, 'Street 2'), (300, 'Mike', 80, 3, 'Street 3'), (400, 'Dan', 50, 4, 'Street 4'); SELECT * FROM person LATERAL VIEW EXPLODE(ARRAY(30, 60)) tabelName AS c_age LATERAL VIEW EXPLODE(ARRAY(40, 80)) AS d_age; +------+-------+-------+--------+-----------+--------+--------+ | id | name | age | class | address | c_age | d_age | +------+-------+-------+--------+-----------+--------+--------+ | 100 | John | 30 | 1 | Street 1 | 30 | 40 | | 100 | John | 30 | 1 | Street 1 | 30 | 80 | | 100 | John | 30 | 1 | Street 1 | 60 | 40 | | 100 | John | 30 | 1 | Street 1 | 60 | 80 | | 200 | Mary | NULL | 1 | Street 2 | 30 | 40 | | 200 | Mary | NULL | 1 | Street 2 | 30 | 80 | | 200 | Mary | NULL | 1 | Street 2 | 60 | 40 | | 200 | Mary | NULL | 1 | Street 2 | 60 | 80 | | 300 | Mike | 80 | 3 | Street 3 | 30 | 40 | | 300 | Mike | 80 | 3 | Street 3 | 30 | 80 | | 300 | Mike | 80 | 3 | Street 3 | 60 | 40 | | 300 | Mike | 80 | 3 | Street 3 | 60 | 80 | | 400 | Dan | 50 | 4 | Street 4 | 30 | 40 | | 400 | Dan | 50 | 4 | Street 4 | 30 | 80 | | 400 | Dan | 50 | 4 | Street 4 | 60 | 40 | | 400 | Dan | 50 | 4 | Street 4 | 60 | 80 | +------+-------+-------+--------+-----------+--------+--------+ SELECT c_age, COUNT(1) FROM person LATERAL VIEW EXPLODE(ARRAY(30, 60)) AS c_age LATERAL VIEW EXPLODE(ARRAY(40, 80)) AS d_age GROUP BY c_age; +--------+-----------+ | c_age | count(1) | +--------+-----------+ | 60 | 8 | | 30 | 8 | +--------+-----------+ SELECT * FROM person LATERAL VIEW EXPLODE(ARRAY()) tabelName AS c_age; +-----+-------+------+--------+----------+--------+ | id | name | age | class | address | c_age | +-----+-------+------+--------+----------+--------+ +-----+-------+------+--------+----------+--------+ SELECT * FROM person LATERAL VIEW OUTER EXPLODE(ARRAY()) tabelName AS c_age; +------+-------+-------+--------+-----------+--------+ | id | name | age | class | address | c_age | +------+-------+-------+--------+-----------+--------+ | 100 | John | 30 | 1 | Street 1 | NULL | | 200 | Mary | NULL | 1 | Street 2 | NULL | | 300 | Mike | 80 | 3 | Street 3 | NULL | | 400 | Dan | 50 | 4 | Street 4 | NULL | +------+-------+-------+--------+-----------+--------+