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SQL-Shell-1.16
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/ SQL::Shell::Manual

NAME

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

SYNOPSIS

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

DESCRIPTION

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.

Connecting

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>

Exploring the schema

show tables

This lists the tables in your database along with other attributes that may be provided by your platform and driver:

DBI:SQLite:dbname=test.db> show tables
+-----------+-------------+--------------------+--------------+---------+
| TABLE_CAT | TABLE_SCHEM | TABLE_NAME         | TABLE_TYPE   | REMARKS |
+-----------+-------------+--------------------+--------------+---------+
| NULL      | main        | sqlite_master      | SYSTEM TABLE | NULL    |
| NULL      | temp        | sqlite_temp_master | SYSTEM TABLE | NULL    |
| NULL      | main        | commands           | TABLE        | NULL    |
+-----------+-------------+--------------------+--------------+---------+

For some database drivers this may include some system tables.

show tablecounts

This lists the tables with a rowcount for each:

DBI:SQLite:dbname=test.db> show tablecounts
+-----------------------------+------+
| table                       | rows |
+-----------------------------+------+
| "main"."sqlite_master"      | 2    |
| "temp"."sqlite_temp_master" | 0    |
| "main"."commands"           | 12   |
+-----------------------------+------+

For some database drivers this may include some system tables. This command does a SELECT COUNT(*) FROM on every table in your database. You may not want to do this on databases with large numbers of tables, and/or tables with large numbers of rows.

show catalogs

If your platform supports it, this shows a listing of available database catalogs.

DBI:ODBC:localdb> show catalogs
+----------------+
| TABLE_CAT      |
+----------------+
| AdventureWorks |
| master         |
| msdb           |
| tempdb         |
+----------------+

show schemas

This command will list the schemas available in your database. Note that this is different from show schema (singular), which shows table descriptions for every table in your schema (see below).

DBI:SQLite:dbname=test.db> show schemas
+-------------+
| TABLE_SCHEM |
+-------------+
| main        |
| temp        |
+-------------+

show tabletypes

List the available table-types in your database.

    DBI:SQLite:dbname=test.db> show tabletypes
    +-----------------+
    | TABLE_TYPE      |
    +-----------------+
    | LOCAL TEMPORARY |
    | SYSTEM TABLE    |
    | TABLE           |
    | VIEW            |
    +-----------------+

desc

Lists the columns in a table:

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

show schema

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  |
+-------------+----------------+------+

Current shell settings (show settings)

To list some sqlsh internal settings:

DBI:SQLite:dbname=test.db> show settings
+------------------+-------+
| PARAMETER        | VALUE |
+------------------+-------+
| auto-commit      | on    |
| delimiter        | \t    |
| enter-whitespace |       |
| escape           | off   |
| longreadlen      | 512   |
| longtruncok      | on    |
| multiline        | off   |
| verbose          | on    |
| width            | 80    |
+------------------+-------+

Note that not all settings are yet included in this output.

Querying the database

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                                |
| show tablecounts | 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                                                  |
+------------------+--------------------------------------------------------------+

BLOB values

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           |
	+-------------+

Values containing non-word characters

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   |
+---------+-------------+

Entering multi-line statements

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(*) |
+----------+
| 12       |
+----------+

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

DBI:Oracle:IFLDEV> set multiline off;

Altering the display mode

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.

Altering the database

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(*) |
+----------+
| 12       |
+----------+

If you prefer, you can switch autocommit on:

set autocommit on
insert ...
update ...

This is the preferred mode of operation when connecting to some database platforms like SQL Server. Depending on the platform, not all commands work within a "transaction", and some platforms prefer that they be run with autocommit on. Your mileage may vary.

Clearing the database

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.

The send and recv commands

These commands were added in v1.16. Their purpose is to give the user more control over how commands are interpreted by the shell before they are sent to the DB without the need to make the shell identify the commands to determine whether to expect output or not. They are intended to deal with platform-specific variations of SQL syntax that aren't covered by the generic command-matching process in sqlsh.

send is used when you don't expect output from the command, and recv is used for cases where the command provides output, and you'd like it rendered and displayed, as if it had come from a select.

Example 1

On IBM Netezza, you can query previously deleted records by giving the database the following command:

set show_deleted_records=TRUE

If you try to do that from sqlsh, it will tell you that the command is not recognized, because sqlsh has a built-in set command, and it is trying to match it to what you have typed at the prompt.

The solution is to use the send command to submit the set expression to the DB without having it intercepted by sqlsh:

send set show_deleted_records=TRUE

Example 2

On SQL Server there are a number of procedure calls that provide output. For instance:

exec xp_cmdshell 'dir *.exe'

or simply

xp_cmdshell 'dir *.exe'

While sqlsh supports the execute command, this is intended to run commands from a local SQL file. In this case, sqlsh would just reply that the command is not recognized. The solution is to use the recv command:

recv exec xp_cmdshell 'dir *.exe'

or recv xp_cmdshell 'dir *.exe'

This will make sqlsh submit the exec expression to the DB as if it were a select command, so that any output is rendered and displayed.

Example 3

Several database platforms allow giving the use command to query a different database. You are in effect switching databases without disconnecting. The command looks as follows:

use MY_DB_NAME

If I give this command while in sqlsh, it will not be recognized, however, I could pass it on to the DB by using send:

send use MY_DB_NAME

In this case we type send instead or recv because we don't expect any output from the use command.

Note that if your DB platform supports the use command, you may also need a command to tell you which database you're currently using. This is platform-dependent, but I will provide an example from SQL Server:

    select dbname() as current_database

Dumping delimited data

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 12 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/

Logging

You can chose to log commands:

log commands logfile.txt

or query results:

log queries dumpfile.txt

or both:

log all history.log

Exporting data as XML

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                                |
| show tablecounts | 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</DESCRIPTION>
        </record>
        <record>
                <COMMAND>show tablecounts</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

Exporting data as SQL

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                                |
| show tablecounts | 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');
INSERT into $table (COMMAND,DESCRIPTION) VALUES ('show tablecounts','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 data

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 12 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.

Manipulating the command history

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

Running batches of commands

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

VERSION

v1.16

AUTHOR

John Alden Miguel Gualdron