docs/source/user-guide/cli.md

<!---
  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.
-->

# DataFusion Command-line Interface

The DataFusion CLI allows SQL queries to be executed by an in-process DataFusion context, or by a distributed
Ballista context.

```
USAGE:
    datafusion-cli [FLAGS] [OPTIONS]

FLAGS:
    -h, --help       Prints help information
    -q, --quiet      Reduce printing other than the results and work quietly
    -V, --version    Prints version information

OPTIONS:
    -c, --batch-size <batch-size>    The batch size of each query, or use DataFusion default
    -p, --data-path <data-path>      Path to your data, default to current directory
    -f, --file <file>...             Execute commands from file(s), then exit
        --format <format>            Output format [default: table]  [possible values: csv, tsv, table, json, ndjson]
        --host <host>                Ballista scheduler host
        --port <port>                Ballista scheduler port
```

## Example

Create a CSV file to query.

```bash
$ echo "1,2" > data.csv
```

```bash
$ datafusion-cli

DataFusion CLI v5.1.0-SNAPSHOT

> CREATE EXTERNAL TABLE foo (a INT, b INT) STORED AS CSV LOCATION 'data.csv';
0 rows in set. Query took 0.001 seconds.

> SELECT * FROM foo;
+---+---+
| a | b |
+---+---+
| 1 | 2 |
+---+---+
1 row in set. Query took 0.017 seconds.
```

## Ballista

The DataFusion CLI can also connect to a Ballista scheduler for query execution.

```bash
datafusion-cli --host localhost --port 50050
```

## Cli commands

Available commands inside DataFusion CLI are:

- Quit

```bash
> \q
```

- Help

```bash
> \?
```

- ListTables

```bash
> \d
```

- DescribeTable

```bash
> \d table_name
```

- QuietMode

```
> \quiet [true|false]
```

- list function

```bash
> \h
```

- Search and describe function

```bash
> \h function_table
```