sql - Online in the Cloud

PROGRAM:

NAME

sql - execute a command on a database determined by a dburl

SYNOPSIS

sql [options] dburl [commands]

sql [options] dburl < commandfile

#!/usr/bin/sql --shebang [options] dburl

DESCRIPTION

GNU sql aims to give a simple, unified interface for accessing databases through all the
different databases' command line clients. So far the focus has been on giving a common
way to specify login information (protocol, username, password, hostname, and port
number), size (database and table size), and running queries.

The database is addressed using a DBURL. If commands are left out you will get that
database's interactive shell.

GNU sql is often used in combination with GNU parallel.

dburl A DBURL has the following syntax: [sql:]vendor://
[[user][:password]@][host][:port]/[database][?sqlquery]

See the section DBURL below.

commands The SQL commands to run. Each argument will have a newline appended.

Example: "SELECT * FROM foo;" "SELECT * FROM bar;"

If the arguments contain '\n' or '\x0a' this will be replaced with a newline:

Example: "SELECT * FROM foo;\n SELECT * FROM bar;"

If no commands are given SQL is read from the keyboard or STDIN.

Example: echo 'SELECT * FROM foo;' | sql mysql:///

--db-size
--dbsize Size of database. Show the size of the database on disk. For Oracle this requires
access to read the table dba_data_files - the user system has that.

--help
-h Print a summary of the options to GNU sql and exit.

--html HTML output. Turn on HTML tabular output.

--show-processlist
--proclist
--listproc
Show the list of running queries.

--show-databases
--showdbs
--list-databases
--listdbs
List the databases (table spaces) in the database.

--show-tables
--list-tables
--table-list
List the tables in the database.

--noheaders
--no-headers
-n Remove headers and footers and print only tuples. Bug in Oracle: it still prints
number of rows found.

-p pass-through
The string following -p will be given to the database connection program as
arguments. Multiple -p's will be joined with space. Example: pass '-U' and the
user name to the program:

-p "-U scott" can also be written -p -U -p scott.

-r Try 3 times. Short version of --retries 3.

--retries ntimes
Try ntimes times. If the client program returns with an error, retry the command.
Default is --retries 1.

--sep string
-s string
Field separator. Use string as separator between columns.

--skip-first-line
Do not use the first line of input (used by GNU sql itself when called with
--shebang).

--table-size
--tablesize
Size of tables. Show the size of the tables in the database.

--verbose
-v Print which command is sent.

--version
-V Print the version GNU sql and exit.

--shebang
-Y GNU sql can be called as a shebang (#!) command as the first line of a script.
Like this:

#!/usr/bin/sql -Y mysql:///

SELECT * FROM foo;

For this to work --shebang or -Y must be set as the first option.

DBURL

A DBURL has the following syntax: [sql:]vendor://
[[user][:password]@][host][:port]/[database][?sqlquery]

To quote special characters use %-encoding specified in
http://tools.ietf.org/html/rfc3986#section-2.1 (E.g. a password containing '/' would
contain '%2F').

Examples:
mysql://scott:[email protected]/mydb
sql:oracle://scott:[email protected]/xe
postgresql://scott:[email protected]/pgdb
pg:///
postgresqlssl://[email protected]:3333/pgdb
sql:sqlite2:////tmp/db.sqlite?SELECT * FROM foo;
sqlite3:///../db.sqlite3?SELECT%20*%20FROM%20foo;

Currently supported vendors: MySQL (mysql), MySQL with SSL (mysqls, mysqlssl), Oracle
(oracle, ora), PostgreSQL (postgresql, pg, pgsql, postgres), PostgreSQL with SSL
(postgresqlssl, pgs, pgsqlssl, postgresssl, pgssl, postgresqls, pgsqls, postgress),
SQLite2 (sqlite, sqlite2), SQLite3 (sqlite3).

Aliases must start with ':' and are read from /etc/sql/aliases and ~/.sql/aliases. The
user's own ~/.sql/aliases should only be readable by the user.

Example of aliases:

:myalias1 pg://scott:[email protected]/pgdb
:myalias2 ora://scott:[email protected]/xe
# Short form of mysql://`whoami`:nopassword@localhost:3306/`whoami`
:myalias3 mysql:///
# Short form of mysql://`whoami`:nopassword@localhost:33333/mydb
:myalias4 mysql://:33333/mydb
# Alias for an alias
:m :myalias4
# the sortest alias possible
: sqlite2:////tmp/db.sqlite
# Including an SQL query
:query sqlite:////tmp/db.sqlite?SELECT * FROM foo;

EXAMPLES

Get an interactive prompt
The most basic use of GNU sql is to get an interactive prompt:

sql sql:oracle://scott:[email protected]/xe

If you have setup an alias you can do:

sql :myora

Run a query
To run a query directly from the command line:

sql :myalias "SELECT * FROM foo;"

Oracle requires newlines after each statement. This can be done like this:

sql :myora "SELECT * FROM foo;" "SELECT * FROM bar;"

Or this:

sql :myora "SELECT * FROM foo;\nSELECT * FROM bar;"

Copy a PostgreSQL database
To copy a PostgreSQL database use pg_dump to generate the dump and GNU sql to import it:

pg_dump pg_database | sql pg://scott:[email protected]/pgdb

Empty all tables in a MySQL database
Using GNU parallel it is easy to empty all tables without dropping them:

sql -n mysql:/// 'show tables' | parallel sql mysql:/// DELETE FROM {};

Drop all tables in a PostgreSQL database
To drop all tables in a PostgreSQL database do:

sql -n pg:/// '\dt' | parallel --colsep '\|' -r sql pg:/// DROP TABLE {2};

Run as a script
Instead of doing:

sql mysql:/// < sqlfile

you can combine the sqlfile with the DBURL to make a UNIX-script. Create a script called
demosql:

#!/usr/bin/sql -Y mysql:///

SELECT * FROM foo;

Then do:

chmod +x demosql; ./demosql

Use --colsep to process multiple columns
Use GNU parallel's --colsep to separate columns:

sql -s '\t' :myalias 'SELECT * FROM foo;' | parallel --colsep '\t' do_stuff {4} {1}

Retry if the connection fails
If the access to the database fails occasionally --retries can help make sure the query
succeeds:

sql --retries 5 :myalias 'SELECT * FROM really_big_foo;'

Get info about the running database system
Show how big the database is:

sql --db-size :myalias

List the tables:

sql --list-tables :myalias

List the size of the tables:

sql --table-size :myalias

List the running processes:

sql --show-processlist :myalias

REPORTING BUGS

GNU sql is part of GNU parallel. Report bugs to <[email protected]>.

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