Project: Apache Spark (App Definition and Development / Streaming & Messaging)
File: sql-ref-syntax-qry-select-lateral-view.md

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 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. 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. ```sql LATERAL VIEW [ OUTER ] generatorfunction ( expression [ , ... ] ) [ tablealias ] 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 `generatorfunction`, which may be used in output rows. We may have multiple aliases if `generatorfunction` have multiple output

```sql 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)) tableName AS c_age LATERAL VIEW EXPLODE(ARRAY(40, 80)) AS d_age; ++-+-+--+--+--+--+ | id | name | age | class | address | cage | dage | ++-+-+--+--+--+--+ | 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()) tableName AS c_age; +--+-++--+-+--+ | id | name | age | class | address | c_age | +--+-++--+-+--+ +--+-++--+-+--+ SELECT * FROM person LATERAL VIEW OUTER EXPLODE(ARRAY()) tableName 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 | ++-+-+--+--+--+ ```