AngersZhuuuu commented on a change in pull request #34821: URL: https://github.com/apache/spark/pull/34821#discussion_r767434768
########## File path: docs/sql-distributed-sql-engine-spark-sql-cli.md ########## @@ -0,0 +1,192 @@ +--- +layout: global +title: Spark SQL CLI +displayTitle: Spark SQL CLI +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. +--- + +* Table of contents +{:toc} + + +The Spark SQL CLI is a convenient tool to run the Hive metastore service in local mode and execute SQL +queries input from the command line. Note that the Spark SQL CLI cannot talk to the Thrift JDBC server. + +To start the Spark SQL CLI, run the following in the Spark directory: + + ./bin/spark-sql + +Configuration of Hive is done by placing your `hive-site.xml`, `core-site.xml` and `hdfs-site.xml` files in `conf/`. + +## Spark SQL Command Line Options + +You may run `./bin/spark-sql --help` for a complete list of all available options. + + CLI options: + -d,--define <key=value> Variable substitution to apply to Hive + commands. e.g. -d A=B or --define A=B + --database <databasename> Specify the database to use + -e <quoted-query-string> SQL from command line + -f <filename> SQL from files + -H,--help Print help information + --hiveconf <property=value> Use value for given property + --hivevar <key=value> Variable substitution to apply to Hive + commands. e.g. --hivevar A=B + -i <filename> Initialization SQL file + -S,--silent Silent mode in interactive shell + -v,--verbose Verbose mode (echo executed SQL to the + console) + +## The hiverc File + +When invoked without the `-i`, the Spark SQL CLI will attempt to load `$HIVE_HOME/bin/.hiverc` and `$HOME/.hiverc` as initialization files. + +## Supported comment types + +<table class="table"> +<tr><th>Comment</th><th>Example</th></tr> +<tr> + <td>simple comment</td> + <td> + <code> + -- This is a simple comment. + <br> + SELECT 1; + </code> + </td> +</tr> +<tr> + <td>bracketed comment</td> + <td> + <code> + /* This is a bracketed comment. */ + <br> + SELECT 1; + </code> + </td> +</tr> +<tr> + <td>nested bracketed comment</td> + <td> + <code> + /* This is a /* nested bracketed comment*/ .*/ + <br> + SELECT 1; + </code> + </td> +</tr> +</table> + +## Spark SQL CLI Interactive Shell Commands + +When `./bin/spark-sql` is run without either the `-e` or `-f` option, it enters interactive shell mode. +Use `;` (semicolon) to terminate commands. Notice: +1. The CLI use `;` to terminate commands only when it's at the end of line, and it's not escaped by `\\;`. +2. `;` is the only way to terminate commands. If the user types `SELECT 1` and presses enter, the console will just wait for input. +3. If the user types multiple commands in one line like `SELECT 1; SELECT 2;`, the commands `SELECT 1` and `SELECT 2` will be executed separatly. +4. If `;` appears within a SQL statement (not the end of the line), then it has no special meanings: + ```sql + -- This is a ; comment + SELECT ';' as a; + ``` + This is just a comment line followed by a SQL query which returns a string literal. + ```sql + /* This is a comment contains ; + */ SELECT 1; + ``` + However, if ';' is the end of the line, it terminates the SQL statement. The example above will be terminated into `/* This is a comment contains ` and `*/ SELECT 1`, Spark will submit these two command and throw parser error (unclosed bracketed comment). + + +<table class="table"> +<tr><th>Command</th><th>Description</th></tr> +<tr> + <td><code>quit</code> or <code>exit</code></td> + <td>Exits the interactive shell.</td> +</tr> +<tr> + <td><code>!<command></code></td> + <td>Executes a shell command from the Spark SQL CLI shell.</td> +</tr> +<tr> + <td><code>dfs <HDFS dfs command></code></td> + <td>Executes a HDFS <a href="https://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-hdfs/HDFSCommands.html#dfs";>dfs command</a> from the Spark SQL CLI shell.</td> +</tr> +<tr> + <td><code><query string></code></td> + <td>Executes a Spark SQL query and prints results to standard output.</td> +</tr> +<tr> + <td><code>source <filepath></code></td> + <td>Executes a script file inside the CLI.</td> +</tr> +</table> + +## Examples + +Example of running a query from the command line: + + ./bin/spark-sql -e 'SELECT COL FROM TBL' + +Example of setting Hive configuration variables: + + ./bin/spark-sql -e 'SELECT COL FROM TBL' --hiveconf hive.exec.scratchdir=/home/my/hive_scratch + +Example of setting Hive configuration variables: + + ./bin/spark-sql -e 'SELECT ${hiveconf:aaa}' --hiveconf aaa=bbb --hiveconf hive.exec.scratchdir=/home/my/hive_scratch + spark-sql> SELECT ${aaa}; + bbb + +Example of setting Hive variables substitution: + + ./bin/spark-sql --hivevar aaa=bbb --define ccc=ddd + spark-sql> SELECT ${aaa}, ${ccc}; + bbb ddd + +Example of dumping data out from a query into a file using silent mode: + + ./bin/spark-sql -S -e 'SELECT COL FROM TBL' > result.txt + +Example of running a script non-interactively from local disk: + + ./bin/spark-sql -f /path/to/spark-sql-script.sql Review comment: > does it always mean local file? can `hadoop-site.xml` change the default file scheme? From the code, it can read hdfs file ``` public int processFile(String fileName) throws IOException { Path path = new Path(fileName); Object fs; if (!path.toUri().isAbsolute()) { fs = FileSystem.getLocal(this.conf); path = ((FileSystem)fs).makeQualified(path); } else { fs = FileSystem.get(path.toUri(), this.conf); } BufferedReader bufferReader = null; boolean var5 = false; int rc; try { bufferReader = new BufferedReader(new InputStreamReader(((FileSystem)fs).open(path))); rc = this.processReader(bufferReader); } finally { IOUtils.closeStream(bufferReader); } return rc; } ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. 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