SQL::Shell::Manual - user guide for sql shell

sqlsh -d DBI:Oracle:IFLDEV -u scott -p tiger

This is a guide to using sqlsh. sqlsh is an interactive shell run from the command-line for workling with databases. It can also be run in "batch mode" taking a list of commands from stdin (using the -i switch) or you can pass a single command to it on the command-line.

Either set a DSN in the environment as DBI_DSN, supply with the -d option or use the connect command:

	unixbox% sqlsh
	unixbox% sqlsh -d DBI:Oracle:IFLDEV -u scott -p tiger

You can also connect from inside sqlsh:

	unixbox% sqlsh
	> connect DBI:Oracle:IFLDEV scott tiger
	DBI:Oracle:IFLDEV> show $dbh Name
	+--------+
	| Name   |
	+--------+
	| IFLDEV |
	+--------+

and disconnect:

	DBI:Oracle:IFLDEV> disconnect                                 
	> show $dbh Name
	Not connected to database.

If you don't supply a password, sqlsh will prompt you:

	unixbox% sqlsh -d DBI:Oracle:IFLDEV -u scott
	Enter password for scott: 

You can specify a blank password by passing -p:

	unixbox% sqlsh -d DBI:Oracle:IFLDEV -u guest -p

From within sqlsh you can get a list of DBI drivers:

	unixbox% sqlsh
	> show drivers

	  CSV
	  DBM
	  ExampleP
	  Excel
	  File
	  Multiplex
	  Oracle
	  Proxy
	  SQLite
	  Sponge
	  mysql

and a list of possible data sources for a driver:

	unixbox% sqlsh
	> show datasources Oracle

	  dbi:Oracle:GISCPS
	  dbi:Oracle:IFL1
	  dbi:Oracle:IFLDEV
	  dbi:Oracle:IFLTEST

Common DBI DSNs include:

	DBI:Oracle:<SID>
	DBI:mysql:<DB>
	DBI:ADO:<DSN>
	DBI:Excel:file=<xls>
	DBI:CSV:f_dir=<dir>
	DBI:SQLite:dbname=<filename>

This lists the tables with a rowcount for each:

	DBI:SQLite:dbname=test.db> show tables                    
	+----------------------+------+
	| table                | rows |
	+----------------------+------+
	| "sqlite_master"      | 1    |
	| "sqlite_temp_master" | 0    |
	| "commands"           | 11   |
	+----------------------+------+

For some database drivers this may include some system tables.

Lists the columns in a table:

	DBI:Oracle:IFLDEV> desc commands
	+-------------+----------------+------+
	| Field       | Type           | Null |
	+-------------+----------------+------+
	| COMMAND     | VARCHAR2(200)  | YES  |
	| DESCRIPTION | VARCHAR2(1020) | YES  |
	+-------------+----------------+------+

Lists the columns in a table, for each table in the schema:

	DBI:Oracle:IFLDEV> show schema

	schema dump
	COMMANDS:
	+-------------+----------------+------+
	| Field       | Type           | Null |
	+-------------+----------------+------+
	| COMMAND     | VARCHAR2(200)  | YES  |
	| DESCRIPTION | VARCHAR2(1020) | YES  |
	+-------------+----------------+------+

	DBI:SQLite:dbname=test.db> select * from commands
	+------------------+--------------------------------------------------------------+
	| command          | desc                                                         |
	+------------------+--------------------------------------------------------------+
	| show drivers     | Displays a list of DBI drivers                               |
	| show datasources | Displays a list of available data sources for a driver       |
	| connect          | Connects to a data source                                    |
	| disconnect       | Disconnects from a data source                               |
	| show tables      | List the tables in the schema with a rowcount for each table |
	| show schema      | Lists the columns in each table in the schema                |
	| desc             | List the columns in a table                                  |
	| set              | Set a parameter                                              |
	| help             | Displays sqlsh help in your $PAGER                           |
	| reload           | Reloads sqlsh                                                |
	| exit             | Quits sqlsh                                                  |
	+------------------+--------------------------------------------------------------+

You can control the amount of BLOB data fetched by setting the longreadlen parameter.

	


	DBI:Oracle:IFLDEV> set longreadlen 4096
	LongReadLen set to '4096'

	DBI:Oracle:IFLDEV> show $dbh LongReadLen
	+-------------+
	| LongReadLen |
	+-------------+
	| 4096        |
	+-------------+

 Note that the C<longtruncok> parameter should also be set (it is by default):

	DBI:Oracle:IFLDEV> show $dbh LongTruncOk
	+-------------+
	| LongTruncOk |
	+-------------+
	| 1           |
	+-------------+

Suppose we have values in our database which contain whitespace characters (e.g. tabs):

	DBI:Oracle:IFLDEV> set enter-whitespace on
	Whitespace may be entered as \n, \r and \t

	DBI:Oracle:IFLDEV> insert into commands(command,description) values('test', 'one\ttwo')
	INSERT commands: 1 rows affected

When we query the table we see these as literal values:

	DBI:Oracle:IFLDEV> select * from commands
	+---------+-------------+
	| COMMAND | DESCRIPTION |
	+---------+-------------+
	| test    | one two     |
	+---------+-------------+

We can instead chose to display them escaped:

	DBI:Oracle:IFLDEV> set escape show-whitespace
	DBI:Oracle:IFLDEV> select * from commands
	+---------+-------------+
	| COMMAND | DESCRIPTION |
	+---------+-------------+
	| test    | one\ttwo    |
	+---------+-------------+

Alternatively we can use uri-escaping:

	DBI:Oracle:IFLDEV> set escape uri-escape on
	DBI:Oracle:IFLDEV> select * from commands
	+---------+-------------+
	| COMMAND | DESCRIPTION |
	+---------+-------------+
	| test    | one%09two   |
	+---------+-------------+

To enable multiline mode:

	DBI:Oracle:IFLDEV> set multiline on 

You can then build up statements over multiple lines, ending with a semicolon, e.g.:

	DBI:Oracle:IFLDEV> select 
	DBI:Oracle:IFLDEV> count(*) 
	DBI:Oracle:IFLDEV> from 
	DBI:Oracle:IFLDEV> commands
	DBI:Oracle:IFLDEV> ;
	+----------+
	| COUNT(*) |
	+----------+
	| 11       |
	+----------+

To disable multiline mode, remember you need to end the statement in a semicolon:

	DBI:Oracle:IFLDEV> set multiline off;

The default (box) display mode is similar to that used by the mysql client - it works well for tables of fairly short values. The record display mode is good for viewing single records:

	DBI:SQLite:dbname=test.db> set display-mode record
	DBI:SQLite:dbname=test.db> select * from commands where command='desc'
	--------------------------------------------------------------------------------
	command | desc
	desc    | List the columns in a table
	--------------------------------------------------------------------------------

The spaced display mode (despite sounding like a description of sqlsh's author) provides a minimum clutter view of the data. The tabbed display mode generally looks horrendous but is useful for a quick cut+paste of delimited values. The sql display mode generates insert statements using a $table placeholder for where the data is to be inserted. The xml display mode generates element-only XML which can be parsed into a list of hashes with XML::Simple.

By default transactions are not automatically committed so you must explicitly commit them:

	DBI:Oracle:IFLDEV> insert into commands(command, description) values ('dump','Writes a table or query results to a delimited file')
	INSERT commands: 1 rows affected

	DBI:Oracle:IFLDEV> commit

and you can roll back mistakes:

	DBI:Oracle:IFLDEV> delete from commands
	DELETE commands: 11 rows affected

	DBI:Oracle:IFLDEV> rollback
	DBI:Oracle:IFLDEV> select count(*) from commands         
	+----------+
	| COUNT(*) |
	+----------+
	| 11       |
	+----------+

If you prefer to live dangerously you can switch autocommit on:

	set autocommit on
	insert ...
	update ...

The wipe tables command can be used to remove all the data each of the tables in the database:

	DBI:Oracle:IFLDEV> wipe tables       
	Wipe all data from:

	  COMMANDS

	Are you sure you want to do this? (type 'yes' if you are) yes

	Wiped all data in database

It prompts you to confirm before anihilating your database.

dump can either be used to dump an entire table:

	dump mytable into export.txt

or the rowset resulting from a query:

	dump select type, count(*) from mytable group by type into histogram.txt delimited by :

An example:

	DBI:SQLite:dbname=test.db> dump commands into commands.csv delimited by ,
	Dumping commands into commands.csv
	Dumped 11 rows into commands.csv

	DBI:SQLite:dbname=test.db> more commands.csv 
	command,desc
	show drivers,Displays a list of DBI drivers
	show datasources,Displays a list of available data sources for a driver
	connect,Connects to a data source
	disconnect,Disconnects from a data source
	show tables,List the tables in the schema with a rowcount for each table
	show schema,Lists the columns in each table in the schema
	desc,List the columns in a table
	set,Set a parameter
	help,Displays sqlsh help in your $PAGER
	reload,Reloads sqlsh
	exit,Quits sqlsh

You can also dump all the tables in a database into a directory:

	dump all tables into dumpdir/

You can chose to log commands:

	log commands logfile.txt

or query results:

	log queries dumpfile.txt

or both:

	log all history.log

	DBI:Oracle:IFLDEV> set log-mode xml 

	DBI:Oracle:IFLDEV> log queries export.xml
	Logging queries to export.xml

	DBI:Oracle:IFLDEV>> select * from commands where command like 'show%'
	+------------------+--------------------------------------------------------------+
	| COMMAND          | DESCRIPTION                                                  |
	+------------------+--------------------------------------------------------------+
	| show drivers     | Displays a list of DBI drivers                               |
	| show datasources | Displays a list of available data sources for a driver       |
	| show tables      | List the tables in the schema with a rowcount for each table |
	| show schema      | Lists the columns in each table in the schema                |
	+------------------+--------------------------------------------------------------+

	DBI:Oracle:IFLDEV>> more export.xml
	<rowset>
	        <record>
	                <COMMAND>show drivers</COMMAND>
	                <DESCRIPTION>Displays a list of DBI drivers</DESCRIPTION>
	        </record>
	        <record>
	                <COMMAND>show datasources</COMMAND>
	                <DESCRIPTION>Displays a list of available data sources for a driver</DESCRIPTION>
	        </record>
	        <record>
	                <COMMAND>show tables</COMMAND>
	                <DESCRIPTION>List the tables in the schema with a rowcount for each table</DESCRIPTION>
	        </record>
	        <record>
	                <COMMAND>show schema</COMMAND>
	                <DESCRIPTION>Lists the columns in each table in the schema</DESCRIPTION>
	        </record>
	</rowset>

	DBI:Oracle:IFLDEV>> no log
	Stopped logging queries

	DBI:Oracle:IFLDEV> set log-mode sql

	DBI:Oracle:IFLDEV> log queries export.sql                           
	Logging queries to export.sql

	DBI:Oracle:IFLDEV>> select * from commands where command like 'show%'
	+------------------+--------------------------------------------------------------+
	| COMMAND          | DESCRIPTION                                                  |
	+------------------+--------------------------------------------------------------+
	| show drivers     | Displays a list of DBI drivers                               |
	| show datasources | Displays a list of available data sources for a driver       |
	| show tables      | List the tables in the schema with a rowcount for each table |
	| show schema      | Lists the columns in each table in the schema                |
	+------------------+--------------------------------------------------------------+

	DBI:Oracle:IFLDEV>> more export.sql                                  
	INSERT into $table (COMMAND,DESCRIPTION) VALUES ('show drivers','Displays a list of DBI drivers');
	INSERT into $table (COMMAND,DESCRIPTION) VALUES ('show datasources','Displays a list of available data sources for a driver');
	INSERT into $table (COMMAND,DESCRIPTION) VALUES ('show tables','List the tables in the schema with a rowcount for each table');
	INSERT into $table (COMMAND,DESCRIPTION) VALUES ('show schema','Lists the columns in each table in the schema');

	DBI:Oracle:IFLDEV>> no log
	Stopped logging queries

You can then replace $table with the table name you want the INSERT stataments to be issued against:

	unixbox% perl -p -i -e 's/\$table/show_commands/' export.sql

Loading a tab-delimited text file is simple:

	load export.txt into mytable

Here's an example:

	DBI:SQLite:dbname=test.db> create table commands(command varchar(50), desc varchar(255))                
	CREATE table commands: 0 rows affected

	DBI:SQLite:dbname=test.db> load commands.tsv into commands
	Loaded 11 rows into commands from commands.tsv

As with dump you can change the delimiter character:

	load export.csv into mytable delimited by ,

You can also specify character set translations:

	load export.txt into mytable from CP1252 to UTF-8

if your database engine cannot do the character set conversions itself. See Locale::Recode for a list of character set names.

You can dump out the history to a file:

	save history to history.txt

You can also load in a set of commands into the history:

	load history from handy_queries.sql

This can be useful in conjunction with log commands. You can clear the history at any time with:

	clear history

and display it with:

	show history

You can execute a sequence of sqlsh commands from a file:

	> execute commands.sqlsh

that might have been generated by save history or log commands. You can also pipe commands into sqlsh on STDIN if you call it with the -i switch:

	unixbox% sqlsh -d DBI:Oracle:IFLDEV -u scott -p tiger -i < commands.sqlsh

$Revision: 1.6 $ on $Date: 2006/08/02 12:01:15 $ by $Author: johna $

John Alden