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### What changes were proposed in this pull request? update sql-ref docs, the following key words will be added in this PR. CASE/ELSE WHEN/THEN MAP KEYS TERMINATED BY NULL DEFINED AS LINES TERMINATED BY ESCAPED BY COLLECTION ITEMS TERMINATED BY PIVOT LATERAL VIEW OUTER? ROW FORMAT SERDE ROW FORMAT DELIMITED FIELDS TERMINATED BY IGNORE NULLS FIRST LAST ### Why are the changes needed? let more users know the sql key words usage ### Does this PR introduce _any_ user-facing change? ![image](https://user-images.githubusercontent.com/46367746/88148830-c6dc1f80-cc31-11ea-81ea-13bc9dc34550.png) ![image](https://user-images.githubusercontent.com/46367746/88148968-fb4fdb80-cc31-11ea-8649-e8297cf5813e.png) ![image](https://user-images.githubusercontent.com/46367746/88149000-073b9d80-cc32-11ea-9aa4-f914ecd72663.png) ![image](https://user-images.githubusercontent.com/46367746/88149021-0f93d880-cc32-11ea-86ed-7db8672b5aac.png) ### How was this patch tested? No Closes #29056 from GuoPhilipse/add-missing-keywords. Lead-authored-by: GuoPhilipse <guofei_ok@126.com> Co-authored-by: GuoPhilipse <46367746+GuoPhilipse@users.noreply.github.com> Signed-off-by: Takeshi Yamamuro <yamamuro@apache.org>
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layout | title | displayTitle | license |
---|---|---|---|
global | LATERAL VIEW Clause | LATERAL VIEW Clause | 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 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.
Syntax
LATERAL VIEW [ OUTER ] generator_function ( expression [ , ... ] ) [ table_alias ] AS column_alias [ , ... ]
Parameters
-
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 ifgenerator_function
have multiple output columns.
Examples
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 |
+------+-------+-------+--------+-----------+--------+