spark-instrumented-optimizer/docs/sql-ref-syntax-qry-select-usedb.md
shivusondur d3eb4c94cc [SPARK-28822][DOC][SQL] Document USE DATABASE in SQL Reference
### What changes were proposed in this pull request?
Added document reference for USE databse sql command

### Why are the changes needed?
For USE database command usage

### Does this PR introduce any user-facing change?
It is adding the USE database sql command refernce information in the doc

### How was this patch tested?
Attached the test snap
![image](https://user-images.githubusercontent.com/7912929/65170499-7242a380-da66-11e9-819c-76df62c86c5a.png)

Closes #25572 from shivusondur/jiraUSEDaBa1.

Lead-authored-by: shivusondur <shivusondur@gmail.com>
Co-authored-by: Xiao Li <gatorsmile@gmail.com>
Signed-off-by: Xiao Li <gatorsmile@gmail.com>
2019-09-19 13:04:17 -07:00

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1.9 KiB
Markdown

---
layout: global
title: USE Database
displayTitle: USE Database
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.
---
### Description
`USE` statement is used to set the current database. After the current database is set,
the unqualified database artifacts such as tables, functions and views that are
referenced by SQLs are resolved from the current database.
The default database name is 'default'.
### Syntax
{% highlight sql %}
USE database_name
{% endhighlight %}
### Parameter
<dl>
<dt><code><em>database_name</em></code></dt>
<dd>
Name of the database will be used. If the database does not exist, an exception will be thrown.
</dd>
</dl>
### Example
{% highlight sql %}
-- Use the 'userdb' which exists.
USE userdb;
+---------+--+
| Result |
+---------+--+
+---------+--+
-- Use the 'userdb1' which doesn't exist
USE userdb1;
Error: org.apache.spark.sql.catalyst.analysis.NoSuchDatabaseException: Database 'userdb1' not found;(state=,code=0)
{% endhighlight %}
### Related statements.
- [CREATE DATABASE](sql-ref-syntax-ddl-create-database.html)
- [DROP DATABASE](sql-ref-syntax-ddl-drop-database.html)
- [CREATE TABLE ](sql-ref-syntax-ddl-create-table.html)