DBD::AnyData(3) User Contributed Perl Documentation DBD::AnyData(3)NAMEDBD::AnyData - DBI access to XML, CSV and other formats
SYNOPSIS
use DBI;
my $dbh = DBI->connect('dbi:AnyData(RaiseError=>1):');
$dbh->func( 'trains', 'CSV', '/users/joe/cars.csv', 'ad_catalog');
$dbh->func( 'bikes', 'XML', [$xml_str], 'ad_import');
$dbh->func( 'cars', 'DBI', $mysql_dbh, 'ad_import');
#
# ... DBI/SQL methods to access/modify the tables 'cars','bikes','trains'
#
print $dbh->func( 'cars', 'HTMLtable', 'ad_export');
or
use DBI;
my $dbh = DBI->connect('dbi:AnyData(RaiseError=>1):');
$dbh->func( 'Pipe', 'data.pipe', 'XML', 'data.xml', 'ad_convert');
or
(many combinations of a dozen other data formats, see below)
DESCRIPTION
The DBD::AnyData module provides a DBI/SQL interface to data in many
formats and from many sources.
Currently supported formats include general format flatfiles (CSV,
Fixed Length, Tab or Pipe "delimited", etc.), specific formats (passwd
files, web logs, etc.), a variety of other kinds of formats (XML, Mp3,
HTML tables), and, for some operations, any DBI accessible database.
The number of supported formats will continue to grow rapidly since
there is an open API making it easy for any author to create additional
format parsers which can be plugged in to AnyData.
Data in these various formats can come from local files, from remote
files, or from perl data structures such as strings and arrays.
Regardless of the format or source of the data, it may be accessed
and/or modified using all standard DBI methods and a subset of SQL
syntax.
In addition to standard database access to files, the module also
supports in-memory tables which allow you to create temporary views; to
combine data from a number of sources; to quickly prototype database
systems; and to display or save the data in any of the supported
formats (e.g. to display data in a CSV file as an HTML table). These
in-memory tables can be created from any combination of DBI databases
or files of any format. They may also be created from perl data
structures which means it's possible to quickly prototype a database
system without any file access or rdbms backend.
The module also supports converting files between any of the supported
formats (e.g. save selected data from MySQL or Oracle to an XML file).
Here a just a few examples of the capabilities:
# SELECT DATA FROM A PASSWD FILE
#
$dbh->func( 'users', 'Passwd', '/etc/passwd', 'ad_catalog');
my $sth = $dbh->prepare("SELECT username,homedir,GID FROM users');
# INSERT A NEW ROW INTO A CSV FILE
#
$dbh->func( 'cars', 'CSV', 'cars.csv', 'ad_catalog');
$dbh->do("INSERT INTO cars VALUES ('Honda','Odyssey')");
# READ A REMOTE XML FILE AND PRINT IT AS AN HTML TABLE
#
print $dbh->func( 'XML', $url, 'HTMLtable', 'ad_convert');
# CONVERT A MYSQL DATABASE INTO XML AND SAVE IT IN A NEW FILE
#
$dbh->func( 'DBI', $mysql_dbh, 'XML', 'data.xml', 'ad_convert');
# CREATE AND ACCESS A VIEW CONTAINING DATA FROM AN ORACLE DATABASE
# AND A TAB DELIMITED FILE
#
$dbh->func( 'combo', 'DBI', $oracle_dbh, 'ad_import');
$dbh->func( 'combo', 'Tab', 'data.tab', 'ad_import');
my $sth = $dbh->prepare("SELECT * FROM combo");
INSTALLATION
To use DBD::AnyData you will need to install these modules, all
available from CPAN and most available from activeState.
* DBI
* DBI::DBD::SqlEngine
* SQL::Statement
* AnyData
* DBD::AnyData
Note: DBI::DBD::SqlEngine is part of the DBI distribution
Some advanced features require additional modules:
remote file access
requires LWP (the libwww bundle)
XML access
requires XML::Parser and XML::Twig
HTML table
access requires HTML::Parser and HTML::TableExtract
HTML table writing
requires CGI
AnyData and DBD::AnyData themselves can either be installed via cpan,
cpanplus or cpanminus, using the distributed Build.PL manually with
perl Build.PL
./Build
./Build test
./Build install
or by copying the AnyData.pm file manually to it's right place within
your perl library path.
QUICK START
The Basics
There are four main steps in using DBD::AnyData in a script:
1. Specify that you want to use the DBI module
2. Create a database handle
3. Specify the tables, files, and formats you want
4. Use DBI/SQL commands to access and/or modify the data
Steps #1, #2, and #3 can be as little as a single line of code each.
Steps #3 and #4 can be omitted in some situations, see the sections
below on "Working with In-Memory Data" and "Converting Data"
Step #1 : Specify that you want to use the DBI module
This step is always the same: just put this at the top of your script:
use DBI;
Step #2 Create a Database Handle
This step can vary slightly depending on your needs but is usually
this:
my $dbh = DBI->connect('dbi:AnyData(RaiseError=>1):');
See the section below on "Connection Options" for other forms of
connecting. See the section below on "Using Multiple Databases" for
cases in which you may be creating more than one database handle.
Step #3 : Specify the tables, files, and formats
This step makes use of one of several methods unique to DBD::AnyData.
These methods use the database handle created in step #2 to make a
func() call and specify the name of the method as the last parameter.
For example the 'ad_catalog' method would be called like this:
$dbh->func( ..., 'ad_catalog')
The ad_catalog() method takes three required parameters and one
optional parameter:
# $table = the name you will use to refer to the table in SQL commands
# $format = the format of the data ('XML', 'CSV', 'Fixed', etc.)
# $file = the name of a local or remote file holding the data
# $flags = an optional hash of flags required by some data formats
$dbh->func( $table, $format, $file, $flags, 'ad_catalog')
# For example:
$dbh->func( 'cars', 'XML', 'cars.xml', 'ad_catalog' )
This specifies that the table name 'cars' will be used to access XML
data stored in the file 'cars.xml'.
Once you have issued a catalog command, you can use the name $table in
SQL commands to access or modify the data in $file. The catalog only
needs to be specified once for a table/file/format combination and can
then be used for an unlimited number of processing commands.
Step #4 : Use DBI/SQL commands to access and/or modify data
DBD::AnyData supports all standard DBI methods and a subset of SQL
syntax. See the section below "SQL Syntax" for a description of the
supported SQL commands. See the DBI documentation for detailed
description of DBI commands.
The do() method can be used to create or drop a table and insert,
delete, or update rows:
$dbh->do("CREATE TABLE ... )
$dbh->do("DROP TABLE ... )
$dbh->do("INSERT INTO ... )
$dbh->do("UPDATE ... )
$dbh->do("DELETE ... )
A combination of the prepare(), execute(), and fetch() methods can be
used to access data:
my $sth = $dbh->prepare("SELECT * FROM cars WHERE make = 'Honda'");
$sth->execute();
while (my $row = $sth->fetchrow_hashref){
print $row->{model};
}
Putting it all together
This is the complete script needed to access data stored in CSV format
in a file called "cars.csv". It prints all data from the "make" and
"model" columns of the database.
# specifies that you will use the DBI module.
use DBI;
# creates a database handle
my $dbh = DBI->connect('dbi:AnyData(RaiseError=>1):');
# specifies the table, format, and file holding the data
$dbh->func( 'cars', 'CSV', 'cars.csv' 'ad_catalog');
# through 8 use DBI and SQL to access data in the file
my $sth = $dbh->prepare("SELECT make, model FROM cars");
$sth->execute();
while (my $row = $sth->fetch) {
print "@$row\n";
}
Customizing table structure
DBD::AnyData uses a number of defaults when it decides how to read data
from a database and in many cases these defaults are all you will need.
However, depending on the format and database you are using, you may
need to specify other features such as column names, record separators,
etc.
You can specify this additional information in the $flags parameter of
the ad_catalog and other DBD::AnyData methods. $flags is always a
reference to a hash, i.e. one or more key value pairs joined with a =>,
separated by commas, and delimited by curly braces:
$flags = { key1 => value1, key2 => value2 ... }
# or in the method call:
$dbh->func( $table, $format, $file, { key1=>,val1 ... }, 'ad_catalog');
Column Names
Some formats have pre-defined column names:
Passwd username
passwd
UID
GID
fullname
homedir
shell
Weblog remotehost
usernname
authuser
date
request
status
bytes
referer
client
Mp3 song
artist
album
year
genre
filename
filesize
Column names for the other formats can either be specified in the
database itself or supplied by you in the $flags parameter.
If the column names are specified in the database, they are taken
from the first record in the database. For example in a CSV (Comma
Separated Values) file or a Fixed Length file, the default is to
treat the first line of the table as the list of column names. In an
HTMLtable file, the default is to look for the first <tr> in the
first table. In an XML file, the default is to use the names of all
attributes and all CDATA and PCDATA elements contained within the
first non-initial tag.
In most cases, this first record that defines the column names is in
the same format as the rest of the table e.g. a CSV string in a CSV
file, a tab delimited string in a Tab delimited file, etc. The one
exception to this is that in a Fixed Length file the first row of the
file can contain a *comma-separated* list of column names, not a
fixed length list. HTMLtable and XML also use other flags to select
the column names (e.g. the number of the table or the depth in the
tree to examine). Please see the documentation for these formats for
further details of how defaults are selected.
For most formats, if the column names are not contained in the first
record in the file, then you can specify them as a comma separated
list in the $flags parameter, for example:
$dbh->func(
'cars',
'Tab',
'data.tab',
{ col_names => 'make,model,year' },
'ad_catalog')
SUPPORTED FORMATS
CSV, Tab, Pipe, Ini, Paragraph
Fixed
Fixed Length format files (where each column is a specified length) are
unique in several respects. First, as mentioned above, if you wish to
include the column names in the file itself, they should be on the
first line of the file as a *comma separated* string.
Secondly, there is a mandatory flag called 'pattern' that you must use
whenever you use the Fixed length format. This flag specifies the
widths of the columns. It uses the standard Perl pack/unpack syntax to
specify the pattern. See the Perl documentation for those commands for
further details. In most cases simply using a capital 'A' followed by
the length of the field suffices:
{ pattern => 'A10 A12 A4' }
This specifies that the table contains three fields with widths of 10,
12, and 14 characters.
XML
HTMLtable
DBI
DBD::AnyData supports importing any DBI database into memory and can
also convert any DBI database into any of the other AnyData formats.
Use the format name 'DBI', and instead of a filename, pass the
ad_import call a connection in whatever database you are using, and
specify a SQL SELECT statement:
my $dbh = DBI->connect('dbi:AnyData:(RaiseError=>1)');
$dbh->func(
'table1',
'DBI',
DBI->connect('dbi:mysql:database=test:(RaiseError=>1)'),
{sql=>"SELECT make, model FROM cars WHERE make = 'honda'"},
'ad_import');
That snippet imports a view from a MySQL database (selecting only the
named columns and the selected rows) into an AnyData in-memory table.
It can then be queried and/or modified in memory and then either
displayed or stored to a file in some other format such as XML.
You may also use a bind_parameters form for the SQL call by passing an
additional flag with an arrayref of the parameters:
{
sql => "SELECT make,model FROM CARS WHERE make = ?"
params => ['honda']
}
To convert from a DBI accessible database such as ORACLE or MySQL to
one of the AnyData formats such as XML you must also include a flag
with the table_name within the database:
my $dbh = DBI->connect('dbi:AnyData:(RaiseError=>1)');
$dbh->func(
'DBI',
DBI->connect('dbi:mysql:database=test:(RaiseError=>1)'),
'XML',
'cars.xml',
{table_name=>'cars'},
'ad_convert');
Or to print out the same data as an HTML table without storing it:
my $dbh = DBI->connect('dbi:AnyData:(RaiseError=>1)');
print $dbh->func(
'DBI',
DBI->connect('dbi:mysql:database=test:(RaiseError=>1)'),
'HTMLtable',
undef,
{table_name=>'cars'},
'ad_convert');
The ad_convert() method works on the entire database. If you need to
convert only a selected portion of the databse, use ad_import() with a
SELECT clause and then ad_export() it to the new format.
The ad_import method by default closes the connection for the imported
database. If you need to continue using the handle for the other
datbase, pass the flag {keep_connection=>1}:
my $dbh = DBI->connect('dbi:AnyData:(RaiseError=>1)');
my $mysql_dbh = DBI->connect('dbi:mysql:database=test:(RaiseError=>1)'),
$dbh->func(
'cars',
'DBI',
$mysql_dbh,
{ keep_connection=>1 },
'ad_import');
#...
$mysql_dbh->disconnect;
Passwd, Weblog, Mp3
Other Formats
DBD::AnyData supports an open API that allows other authors to build
support for other formats. This means that the list of supported
formats will continually grow. At the moment Wes Hardaker is working on
AnyData::Format::SNMP and Earl Cahill is working on
AnyData::Format::Storable. Anyone who is interested in working on a new
format module, please open a ticket with an appropriate patch or write
to dbi-dev@perl.org.
FURTHER DETAILS
Converting between formats
The $dbh->func(...,'ad_convert') method provides a one-step way to
convert between any of the data formats supported by DBD::AnyData. For
example: read a CSV file and save it as an XML file or vice versa. See
the section below on "convert" for details. See the section on
"Working with other DBI databases" for information on converting data
from ORACLE, or MySQL or almost any other database into XML, CSV, or
any of the DBD::AnyData formats.
Using remote files
You can import remote files accessible by FTP or HTTP directly into a
DBD::AnyData in memory database using 'ad_import' or you can use
ad_convert to print the remote files as strings or save them to a local
file. If the $file parameter of ad_import or ad_convert starts with
"ftp" or "http", DBD::AnyData will call LWP behind the scenes and fetch
the file.
This will fetch the remote file, parse its XML, and provide you with an
in-memory table which you can query with DBI/SQL or save to a local
file:
$dbh->func(
'news',
'XML',
'http://www.somewhere.org/files/news.xml',
'ad_import');
This will fetch the remote file, parse its XML, and print it out as an
HTML table:
print $dbh->func(
'XML',
'http://www.somewhere.org/files/news.xml',
'HTMLtable',
'ad_convert');
If the remote file requires authorization, you can include values for
"user" and "pass" in the $flags parameter:
$dbh->func(
'news',
'XML',
'http://www.somewhere.org/news.xml',
{ user => 'fred', passwd => 'x9y77d' },
'ad_import');
Working with in-memory tables
In addition to normal file storage databases, DBD::AnyData supports
databases that are stored and modified in-memory. You may either simply
query the databases and then close them, or you can use the ad_export
method to display data to the screen or save it to a file. There are a
variety of reasons you might want to work with in-memory databases,
including:
Prototyping
quickly create a database from a string, an array, or the DATA
section of a script without needing any file access or rdbms.
Creating Views
pull selected columns and selected rows from an ORACLE or MySQL
database en masse and work with them in memory rather than having
to use the full database.
Combining Data from multiple formats
create a single in-memory table by importing selected columns and
rows from e.g. an XML file, an Oracle database, and a CSV file.
Rollback/Commit
You can make multiple changes to the in-memory database and then,
depending on the sucess or failure of those changes either commit
by using export to save the changes to disk or skip export which
effectively rolls back the database to its state before the import.
In-memory tables may be modified with DBI/SQL commands and can then be
either printed to the screen or saved as a file in any of the AnyData
formats. (see the ad_export method below)
In-memory tables may be created in several ways:
1. Create and populate the table from one or more local or remote files
2. Create and populate the table from a string
3. Create and populate the table from an array
4. Use DBI/SQL commands to create & populate the table
Creating in-memory tables from local or remote files
You can create an in-memory table from a string in a specified
format, Note: the string should be enclosed in square brackets.
This reads a CSV file into an in-memory table. Further access and
modification takes place in-memory without further file access
unless you specifically use ad_export to save the table to a file.
# CREATE A TABLE FROM A LOCAL FILE
$dbh->func( 'test2', 'CSV', $filename, 'ad_import');
# CREATE A TABLE FROM A REMOTE FILE
$dbh->func( 'test2', 'CSV', $url, 'ad_import');
See the section on "Remote File Access" for further details of
using remote Files.
Creating an in-memory table from Strings
You can create an in-memory table from a string in a specified
format, Note: the string should be enclosed in square brackets.
This example creates an in-memory table from a CSV string:
# CREATE A TABLE FROM A CSV STRING
$dbh->func( 'test2', 'CSV',
["id,phrase\n1,foo\n2,bar"],
'ad_import');
Creating an in-memory table from the DATA section of a script
Perl has the really cool feature that if you put text after the
marker __END__, you can access that text as if it were from a file
using the DATA array. This can be great for quick prototyping.
For example this is a complete script to build and access a small
table and print out "Just Another Perl Hacker":
use DBI;
my $dbh=DBI->connect('dbi:AnyData(RaiseError=>1):');
$dbh->func( 'test', 'XML', [<DATA>], 'ad_import');
print $dbh->selectcol_arrayref(qq{
SELECT phrase FROM test WHERE id = 2
})->[0];
__END__
<phrases>
<phrase id="1">Hello World!</phrase>
<phrase id="2">Just Another Perl Hacker!</phrase>
</phrases>
The same idea can be used with DATA sections of any size in any of
the supported formats.
Creating an in-memory table from Arrays
In-memory tables may also be created from arrays. Or, more
technically, from references to arrays. The array should consist
of rows which are themselves references to arrays of the row
values. The first row should be column names.
For example:
# CREATE A TABLE FROM AN ARRAY
$dbh->func( 'test3', 'ARRAY',
[
['id','phrase'],
[1,'foo'],
[2,'bar']
],
'ad_import');
Creating an in-memory table from DBI/SQL commands
If you do not use ad_catalog or ad_import to associate a table name
with a file, then the table will be an in-memory table, so you can
just start right out by using it in DBI/SQL commands:
# CREATE & POPULATE A TABLE FROM DBI/SQL COMMANDS
use DBI;
my $dbh = DBI->connect('dbi:AnyData(RaiseError=>1):');
$dbh->do("CREATE TABLE test (id TEXT,phrase TEXT)");
$dbh->do("INSERT INTO test VALUES (1,'foo')");
$dbh->do("INSERT INTO test VALUES (2,'bar')");
$dbh->do("UPDATE test SET phrase='baz' WHERE id = '2'");
$dbh->do("DELETE FROM test WHERE id = '1'");
Using Multiple Databases, Simulating Joins
You may access any number of databases within a single script and can
mix and match from the various data formats.
For example, this creates two in-memory tables from two different data
formats
$dbh->func( 'classes', 'CSV', 'classes.csv' 'ad_import');
$dbh->func( 'profs', 'XML', 'profs.xml', 'ad_import');
You can also import columns from several different formats into a
single table. For example this imports data from an XML file, a CSV
file and a Pipe delimited file into a single in-memory database. Note
that the $table parameter is the same in each call so the data from
each import will be appended into that one table.
$dbh->func( 'test', 'XML', [$xmlStr], 'ad_import');
$dbh->func( 'test', 'CSV', [$csvStr], 'ad_import');
$dbh->func( 'test', 'Pipe', [$pipeStr], 'ad_import');
When you import more than one table into a single table like this, the
resulting table will be a cross join unless you supply a lookup_key
flag. If a lookup_key is supplied, then a the resulting table will be
a full outer join on that key column. This feature is experimental for
the time being but should work as expected unless there are columns
other than the key column with the same names in the various tables.
You can specify that the joined table will only contain certain columns
by creating a blank empty table before doing the imports. You can
specify only certain rows with the sql flag. For example:
$dbh->func('test','ARRAY',[],{col_names=>'foo,bar'baz'}, 'ad_import');
$dbh->func('test','XML',$file1,{lookup_key=>'baz'},'ad_import');
$dbh->func('test','CSV',$file1,{lookup_key=>'baz'},'ad_import');
DBD::AnyData does not currently support using multiple tables in a
single SQL statement. However it does support using multiple tables
and querying them separately with different SQL statements. This means
you can simulate joins by creating two statement handles and using the
values from the first handle as a lookup key for the second handle.
Like this:
$dbh->func( 'classes', 'CSV', 'classes.csv' 'ad_import');
$dbh->func( 'profs', 'XML', 'profs.xml', 'ad_import');
my $classes_sth = $dbh->prepare( "SELECT pid,title FROM classes" );
my $profs_sth = $dbh->prepare( "SELECT name FROM profs WHERE pid = ?" );
$classes_sth->execute;
while (my($pid,$class_title) = $classes_sth->fetchrow_array) {
$profs_sth->execute($pid);
my $row = $profs_sth->fetchrow_arrayref;
my $prof_name = $row ? $row->[0] : '';
print "$class_title : $prof_name\n";
}
# That will produce the same results as:
SELECT classes.title,profs.name FROM classes,profs WHERE pid = pid
REFERENCE
Overview of DBD::AnyData Methods
DBD::AnyData makes use of five methods not found in other drivers:
ad_catalog specifies a file to be used for DBI/SQL continuous file
access
ad_import imports data into an in-memory table
ad_export exports data from an in-memory table to a file
ad_clear clears an in-memory table (deletes it from memory)
ad_convert converts data from one format to another and either saves
it in a new file or returns it as a string
These methods are called using DBI func(), for example:
$dbh->func( $table, $format, 'ad_export');
# Here are the parameters for the various methods:
$dbh->func( $table, $format, $file, $flags, 'ad_catalog');
$dbh->func( $table, $format, $data, $flags, 'ad_import');
$dbh->func( $source_format, $source_data,
$target_format, $target_file,
$source_flags, $target_flags,
'ad_convert');
$dbh->func( $table, $format, $file, $flags, 'ad_export');
$dbh->func( $table, 'ad_clear' );
# $table is a valid SQL table name
# $format is one of the AnyData formats ('XML','CSV',etc.)
# $file is a valid file name (relative or absolute) on the local computer
# $flags is a hashref containing key/value pairs, e.g.
{ col_names => 'make,model,year', pattern => 'A10 A12 A4' }
# $data is one of:
# * a valid file name (relative or absolute) on the local computer
# * a valid absolute FTP or HTTP URL
# * an arrayref containing arrayrefs of rows with column names first
# [
# ['make','model'],
# ['Honda','Odyssy'],
# ['Ford','Suburban'],
# ]
# * an arrayref containing a string in a specified format
# CSV : ["id,phrase\n1,foo\n2,bar"]
# Pipe : ["id|phrase\n1|foo\n2|bar"]
# * a reference to the DATA section of a file
# [<DATA>]
# * a DBI Database handle
# DBI->connect('dbi:mysql:database=...)
The ad_catalog method is the standard way to treat files as databases.
Each time you access data, it is read from the file and each time you
modify data, it is written to the file. The entire file is never read
en masse into memory unless you explicitly request it.
The ad_import method can import data from local or remote files, from
any other DBI accessible database, from perl data structures such as
arrays and strings. You may import an entire table or only the columns
and rows you specify. If the data is imported from a file, all of the
data you select is read into memory when you call ad_import so this
should not be done with selections larger than will fit in your memory.
:-). All accessing and modification is done in memory. If you want to
save the results of any changes, you will need to call ad_export
explicitly.
Not all formats and data sources will work with all methods. Here is a
summary of what will work. "all sources" includes local files, remote
files, any DBI accessible database, perl arrayrefs, perl strings.
Import From all formats, all sources
Convert From all formats, all sources
Convert To all formats except DBI, local files, arrays or strings only
Export To all formats except DBI, local files, arrays or strings only
Catalog all formats except DBI, XML, HTMLtable, Mp3, ARRAY,
local files only
connect
The DBI->connect call
ad_catalog
PURPOSE:
Creates an association betweeen a table name, a data format, and a file.
SYNTAX:
$dbh->func( $table, $format, $file, $flags, 'ad_catalog' )
PARAMETERS:
$table = the name of the table to be used in SQL commands
$format = an AnyData format ('XML','CSV', etc.)
$file = the name of a local file (either full path or relative)
$flags = a optional hashref of column names or other values
EXAMPLE:
This specifies that any DBI/SQL statements to the table
'cars' will access and/or modify XML data in the file
'/users/me/data.xml'
$dbh->func( 'cars', 'XML', '/usrs/me/data.xml', 'ad_catalog' )
REMARKS:
The format may be any AnyData format *except* DBI, XML, HTMLtable,
and MP3.
ad_import
PURPOSE:
Imports data from any source and any format into an in-memory table.
SYNTAX:
$dbh->func( $table, $format, $data_source, $flags, 'ad_import' )
PARAMETERS:
$table = the name of the table to be used in SQL commands
$format = an AnyData format ('XML','CSV', etc.)
$data_source = $file_name
or $url
or [$string]
or [<DATA>]
or $reference_to_an array of arrays
or $DBI_database_handle
(See section "Data Sources" for more specifics of $data_source)
EXAMPLES:
$dbh->func( 'cars', 'XML', '/usrs/me/data.xml', 'ad_import' )
For further examples, see sections on "In-Memory Tables",
"Remote Files", "DBI databases".
ad_export
PURPOSE:
Converts an in-memory table into a specified format and either saves
it to a file or returns it as a string.
SYNTAX:
$dbh->func( $table, $format, $file, $flags, 'ad_export' )
OR
my $string = $dbh->func( $table, $format, $flags, 'ad_export' )
PARAMETERS:
$table = the name of the in-memory table to export
$format = an AnyData format ('XML','CSV', etc.)
$file = the name of a local file (either full path or relative)
EXAMPLES:
Save a table as an XML file:
$dbh->func( 'cars', 'XML', '/usrs/me/data.xml', 'ad_export' )
Print a table as an HTML table
print $dbh->func( 'cars', 'HTMLtable', 'ad_export' )
ad_convert
PURPOSE:
Converts data from one format into another and either returns it
as a string in the new format or saves it to a file in the new
format.
SYNTAX:
my $str = $dbh->func(
$source_format,
$data_source
$target_format,
$source_flags,
$target_flags,
'ad_convert' );
OR
$dbh->func(
$source_format,
$data_source
$target_format,
$target_file,
$source_flags,
$target_flags,
'ad_convert' );
PARAMETERS:
$source_format = AnyData format ('XML','CSV', etc.) of the source db
$target_format = AnyData format ('XML','CSV', etc.) of the target db
$target_file = name of file to store converted data in
$data_source = $file_name
or $url
or [$string]
or [<DATA>]
or $reference_to_an array of arrays
or $DBI_database_handle
(See section "Data Sources" for more specifics of $data_source)
EXAMPLES:
# CONVERT A CSV FILE TO AN XML FILE
#
$dbh->func( 'CSV', 'data.csv', 'XML', 'data.xml', 'ad_convert');
# CONVERT AN ARRAYREF TO AN HTML TABLE AND PRINT IT
#
print $dbh->func( 'ARRAY', $aryref, 'HTMLtable', 'ad_convert');
# CONVERT AN ARRAYREF TO XML AND SAVE IT IN A FILE
#
$dbh->func( 'ARRAY', $aryref, 'XML', 'data.xml', 'ad_convert');
# CONVERT A SELECTION FROM A MySQL DATABASE TO XML
# AND SAVE IT IN A FILE
#
$dbh->func(
'DBI',
$mysql_dbh,
'XML',
'data.xml',
{sql=>"SELECT make,model FROM CARS where year > 1996"}
'ad_convert');
REMARKS
The format 'DBI' (any DBI accessible database) may be used as the
source of a conversion, but not as the target of a conversion.
The format 'ARRAY' may be used to indicate that the source of the
conversion is a reference to an array. Or that the result of the
conversion should be returned as an array reference. (See above,
working with in-memory database for information on the structure of
the array reference).
Data Sources
The ad_import and ad_convert methods can take data from many
sources, including local files, remote files, strings, arrays,
any DBI accessible database, the DATA section of a script.
The $data_source parameter to ad_import and ad_convert will
vary depending on the specific data source, see below.
Local Files
A string containing the name of a local file. It may either
be a full path, or a path or file relative to the currently
defined f_dir (see ?);
e.g. '/users/me/data.xml'
Remote Files
A string containing the url of the data. Must start with
'ftp://' or 'http://'
e.g. 'http://www.somewhere.org/misc/news.xml'
Arrays of Arrays
A reference to an array of data. Each row of the data is
a reference to an array of values. The first row is the
column names. E.G.:
[
['make','model'],
['Honda','Odyssy'],
['Ford','Suburban'],
]
Strings
A string in the specified format including all field and record
separators. The string should be the only row in an array reference
(i.e. it should be enclosed in square brackets)
e.g. a CSV string
["id,phrase\n1,foo\n2,bar"]
or in Pipe Delimited string
["id|phrase\n1|foo\n2|bar"]
The DATA section of a file
A reference to the array obtained from the lines after
__END__ in a script.
[<DATA>]
DBI Databases
A database handle for a specified rdbms.
DBI->connect('dbi:mysql:database=...)
ad_clear
PURPOSE:
Clears an in-memory table (deletes it from memory)
SYNTAX:
$dbh->func( $table, 'ad_clear' )
PARAMETERS:
$table = the name of the in-memory table to clear
REMARKS:
In-memory tables will be deleted from memory automatically when the
database handle used to create them goes out of scope. They will also
be deleted if you call $dbh->disconnect() on the database handle
used to create them. The ad_clear method is a way to free up memory
if you intend to keep using the database handle but no longer need a
given table. As with other (all?) Perl memory operations, this frees
memory for the remainder of your perl script to use but does not decrease
the total amount of system memory used by the script.
SQL Syntax
Currently only a limited subset of SQL commands are supported.
Only a single table may be used in each command. This means
That there are *no joins*, but see the section above on simulating
joins. In coming months additional SQL capabilities will be added,
so keep your eyes out for ANNOUNCE message on usenet or the dbi-users
mailing list (see below "Getting More Help").
Here is a brief synopsis, please see the documentation for
SQL::Statement for a more complete description of these commands.
CREATE TABLE $table
( $col1 $type1, ..., $colN $typeN,
[ PRIMARY KEY ($col1, ... $colM) ] )
DROP TABLE $table
INSERT INTO $table
[ ( $col1, ..., $colN ) ]
VALUES ( $val1, ... $valN )
DELETE FROM $table
[ WHERE $wclause ]
UPDATE $table
SET $col1 = $val1, ... $colN = $valN
[ WHERE $wclause ]
SELECT [DISTINCT] $col1, ... $colN
FROM $table
[ WHERE $wclause ]
[ ORDER BY $ocol1 [ASC|DESC], ... $ocolM [ASC|DESC] ]
$wclause [NOT] $col $op $val|$col
[ AND|OR $wclause2 ... AND|OR $wclauseN ]
$op = | <> | < | > | <= | >=
| IS NULL | IS NOT NULL | LIKE | CLIKE
The "CLIKE" operator works exactly like "LIKE" but is case insensitive.
BUGS
Please report any bugs or feature requests to "bug-dbd-anydata at
rt.cpan.org", or through the web interface at
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=DBD-AnyData
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=DBD-AnyData>. I will
be notified, and then you'll automatically be notified of progress on
your bug as I make changes.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc DBD::AnyData
You can also look for information at:
· RT: CPAN's request tracker
http://rt.cpan.org/NoAuth/Bugs.html?Dist=DBD-AnyData
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=DBD-AnyData>
· AnnoCPAN: Annotated CPAN documentation
http://annocpan.org/dist/DBD-AnyData <http://annocpan.org/dist/DBD-
AnyData>
· CPAN Ratings
http://cpanratings.perl.org/d/DBD-AnyData
<http://cpanratings.perl.org/d/DBD-AnyData>
· Search CPAN
http://search.cpan.org/dist/DBD-AnyData/
<http://search.cpan.org/dist/DBD-AnyData/>
ACKNOWLEDGEMENTS
Many people have contributed ideas and code, found bugs, and generally
been supportive including Tom Lowery, Andy Duncan, Randal Schwartz,
Michel Rodriguez, Wes Hardraker, Bob Starr, Earl Cahill, Bryan Fife,
Matt Sisk, Matthew Wickline, Wolfgang Weisseberg. Thanks to Jochen
Weidmann for DBD::File and SQL::Statement and of course Tim Bunce and
Alligator Descartes for DBI and its documentation.
AUTHOR & COPYRIGHT
Copyright 2000, Jeff Zucker <jeff@vpservices.com>
Copyright 2010, Jens Rehsack <rehsack@cpan.org>
This program is free software; you can redistribute it and/or modify it
under the terms of either: the GNU General Public License as published
by the Free Software Foundation; or the Artistic License.
See http://dev.perl.org/licenses/ for more information.
All rights reserved
perl v5.14.1 2010-07-17 DBD::AnyData(3)
