Spark SQL Guide

Spark SQL CLI

The Spark SQL CLI is a convenient interactive command tool to run the Hive metastore service 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.

Path interpretation

Spark SQL CLI supports running SQL from initialization script file(-i) or normal SQL file(-f), If path url don’t have a scheme component, the path will be handled as local file. For example: /path/to/spark-sql-cli.sql equals to file:///path/to/spark-sql-cli.sql. User also can use Hadoop supported filesystems such as s3://<mys3bucket>/path/to/spark-sql-cli.sql or hdfs://<namenode>:<port>/path/to/spark-sql-cli.sql.

Supported comment types

CommentExample
simple comment -- This is a simple comment.
SELECT 1;
bracketed comment /* This is a bracketed comment. */
SELECT 1;
nested bracketed comment /* This is a /* nested bracketed comment*/ .*/
SELECT 1;

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 separately.
  4. If ; appears within a SQL statement (not the end of the line), then it has no special meanings: 
    -- This is a ; comment
SELECT ';' as a;

    This is just a comment line followed by a SQL query which returns a string literal.

    /* 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 commands separated and throw parser error (unclosed bracketed comment and Syntax error at or near '*/').

CommandDescription
quit or exit Exits the interactive shell.
!<command> Executes a shell command from the Spark SQL CLI shell.
dfs <HDFS dfs command> Executes a HDFS dfs command from the Spark SQL CLI shell.
<query string> Executes a Spark SQL query and prints results to standard output.
source <filepath> Executes a script file inside the CLI.

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 and using it in the SQL query:

./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:

./bin/spark-sql -f /path/to/spark-sql-script.sql

Example of running an initialization script before entering interactive mode:

./bin/spark-sql -i /path/to/spark-sql-init.sql

Example of entering interactive mode:

./bin/spark-sql
spark-sql> SELECT 1;
1
spark-sql> -- This is a simple comment.
spark-sql> SELECT 1;
1

Example of entering interactive mode with escape ; in comment:

./bin/spark-sql
spark-sql>/* This is a comment contains \\;
         > It won't be terminated by \\; */
         > SELECT 1;
1
  翻译：