spark-instrumented-optimizer/docs/sql-ref-syntax-ddl-drop-table.md
shivusondur f29a979e42 [SPARK-28798][DOC][SQL] Document DROP TABLE/VIEW statement in SQL Reference
### What changes were proposed in this pull request?
Added doc for DROP TABLE and DROP VIEW sql command

### Why are the changes needed?
For reference DROP TABLE  or DROP VIEW in spark-sql

### Does this PR introduce any user-facing change?
It updates DROP TABLE  or DROP VIEW reference doc

### How was this patch tested?
<details>
<summary> Attached the Snap</summary>

DROP TABLE

![image](https://user-images.githubusercontent.com/7912929/67884038-2443b400-fb6b-11e9-9773-b21dae398789.png)
![image](https://user-images.githubusercontent.com/7912929/67797387-aa96c200-faa7-11e9-90d4-fa8b7c6a4ec7.png)

DROP VIEW
![image](https://user-images.githubusercontent.com/7912929/67797463-c306dc80-faa7-11e9-96ec-e2f2e89d0db8.png)
![image](https://user-images.githubusercontent.com/7912929/67797648-1ed16580-faa8-11e9-9d32-19106326e3d9.png)

</details>

Closes #25533 from shivusondur/jiraUSEDB.

Authored-by: shivusondur <shivusondur@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
2019-11-04 11:52:19 -06:00

2.6 KiB

layout title displayTitle license
global DROP TABLE DROP TABLE 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

DROP TABLE deletes the table and removes the directory associated with the table from the file system if the table is not EXTERNAL table. If the table is not present it throws an exception.

In case of an external table, only the associated metadata information is removed from the metastore database.

Syntax

{% highlight sql %} DROP TABLE [IF EXISTS] [database_name.]table_name {% endhighlight %}

Parameter

IF EXISTS
If specified, no exception is thrown when the table does not exists.
database_name
Specifies the database name where table is present.
table_name
Specifies the table name to be dropped.

Example

{% highlight sql %} -- Assumes a table named employeetable exists. DROP TABLE employeetable; +---------+--+ | Result | +---------+--+ +---------+--+

-- Assumes a table named employeetable exists in the userdb database DROP TABLE userdb.employeetable; +---------+--+ | Result | +---------+--+ +---------+--+

-- Assumes a table named employeetable does not exists. -- Throws exception DROP TABLE employeetable; Error: org.apache.spark.sql.AnalysisException: Table or view not found: employeetable; (state=,code=0)

-- Assumes a table named employeetable does not exists,Try with IF EXISTS -- this time it will not throw exception DROP TABLE IF EXISTS employeetable; +---------+--+ | Result | +---------+--+ +---------+--+

{% endhighlight %}