NAME
SQL::Translator - manipulate structured data definitions (SQL and more)
SYNOPSIS
use SQL::Translator;
my $translator = SQL::Translator->new(
# Print debug info
debug => 1,
# Print Parse::RecDescent trace
trace => 0,
# Don't include comments in output
no_comments => 0,
# Print name mutations, conflicts
show_warnings => 0,
# Add "drop table" statements
add_drop_table => 1,
# to quote or not to quote, thats the question
quote_identifiers => 1,
# Validate schema object
validate => 1,
# Make all table names CAPS in producers which support this option
format_table_name => sub {my $tablename = shift; return uc($tablename)},
# Null-op formatting, only here for documentation's sake
format_package_name => sub {return shift},
format_fk_name => sub {return shift},
format_pk_name => sub {return shift},
);
my $output = $translator->translate(
from => 'MySQL',
to => 'Oracle',
# Or an arrayref of filenames, i.e. [ $file1, $file2, $file3 ]
filename => $file,
) or die $translator->error;
print $output;
DESCRIPTION
This documentation covers the API for SQL::Translator. For a more general discussion of how to use the modules and scripts, please see SQL::Translator::Manual.
SQL::Translator is a group of Perl modules that converts vendor-specific SQL table definitions into other formats, such as other vendor-specific SQL, ER diagrams, documentation (POD and HTML), XML, and Class::DBI classes. The main focus of SQL::Translator is SQL, but parsers exist for other structured data formats, including Excel spreadsheets and arbitrarily delimited text files. Through the separation of the code into parsers and producers with an object model in between, it's possible to combine any parser with any producer, to plug in custom parsers or producers, or to manipulate the parsed data via the built-in object model. Presently only the definition parts of SQL are handled (CREATE, ALTER), not the manipulation of data (INSERT, UPDATE, DELETE).
CONSTRUCTOR
The constructor is called new
, and accepts a optional hash of options. Valid options are:
parser / from
parser_args
producer / to
producer_args
filters
filename / file
data
debug
add_drop_table
quote_identifiers
quote_table_names (DEPRECATED)
quote_field_names (DEPRECATED)
no_comments
trace
validate
All options are, well, optional; these attributes can be set via instance methods. Internally, they are; no (non-syntactical) advantage is gained by passing options to the constructor.
METHODS
add_drop_table
Toggles whether or not to add "DROP TABLE" statements just before the create definitions.
quote_identifiers
Toggles whether or not to quote identifiers (table, column, constraint, etc.) with a quoting mechanism suitable for the chosen Producer. The default (true) is to quote them.
quote_table_names
DEPRECATED - A legacy proxy to "quote_identifiers"
quote_field_names
DEPRECATED - A legacy proxy to "quote_identifiers"
no_comments
Toggles whether to print comments in the output. Accepts a true or false value, returns the current value.
producer
The producer
method is an accessor/mutator, used to retrieve or define what subroutine is called to produce the output. A subroutine defined as a producer will be invoked as a function (not a method) and passed its container SQL::Translator
instance, which it should call the schema
method on, to get the SQL::Translator::Schema
generated by the parser. It is expected that the function transform the schema structure to a string. The SQL::Translator
instance is also useful for informational purposes; for example, the type of the parser can be retrieved using the parser_type
method, and the error
and debug
methods can be called when needed.
When defining a producer, one of several things can be passed in: A module name (e.g., My::Groovy::Producer
), a module name relative to the SQL::Translator::Producer
namespace (e.g., MySQL
), a module name and function combination (My::Groovy::Producer::transmogrify
), or a reference to an anonymous subroutine. If a full module name is passed in (for the purposes of this method, a string containing "::" is considered to be a module name), it is treated as a package, and a function called "produce" will be invoked: $modulename::produce
. If $modulename cannot be loaded, the final portion is stripped off and treated as a function. In other words, if there is no file named My/Groovy/Producer/transmogrify.pm, SQL::Translator
will attempt to load My/Groovy/Producer.pm and use transmogrify
as the name of the function, instead of the default produce
.
my $tr = SQL::Translator->new;
# This will invoke My::Groovy::Producer::produce($tr, $data)
$tr->producer("My::Groovy::Producer");
# This will invoke SQL::Translator::Producer::Sybase::produce($tr, $data)
$tr->producer("Sybase");
# This will invoke My::Groovy::Producer::transmogrify($tr, $data),
# assuming that My::Groovy::Producer::transmogrify is not a module
# on disk.
$tr->producer("My::Groovy::Producer::transmogrify");
# This will invoke the referenced subroutine directly, as
# $subref->($tr, $data);
$tr->producer(\&my_producer);
There is also a method named producer_type
, which is a string containing the classname to which the above produce
function belongs. In the case of anonymous subroutines, this method returns the string "CODE".
Finally, there is a method named producer_args
, which is both an accessor and a mutator. Arbitrary data may be stored in name => value pairs for the producer subroutine to access:
sub My::Random::producer {
my ($tr, $data) = @_;
my $pr_args = $tr->producer_args();
# $pr_args is a hashref.
Extra data passed to the producer
method is passed to producer_args
:
$tr->producer("xSV", delimiter => ',\s*');
# In SQL::Translator::Producer::xSV:
my $args = $tr->producer_args;
my $delimiter = $args->{'delimiter'}; # value is ,\s*
parser
The parser
method defines or retrieves a subroutine that will be called to perform the parsing. The basic idea is the same as that of producer
(see above), except the default subroutine name is "parse", and will be invoked as $module_name::parse($tr, $data)
. Also, the parser subroutine will be passed a string containing the entirety of the data to be parsed.
# Invokes SQL::Translator::Parser::MySQL::parse()
$tr->parser("MySQL");
# Invokes My::Groovy::Parser::parse()
$tr->parser("My::Groovy::Parser");
# Invoke an anonymous subroutine directly
$tr->parser(sub {
my $dumper = Data::Dumper->new([ $_[1] ], [ "SQL" ]);
$dumper->Purity(1)->Terse(1)->Deepcopy(1);
return $dumper->Dump;
});
There is also parser_type
and parser_args
, which perform analogously to producer_type
and producer_args
filters
Set or retreive the filters to run over the schema during the translation, before the producer creates its output. Filters are sub routines called, in order, with the schema object to filter as the 1st arg and a hash of options (passed as a list) for the rest of the args. They are free to do whatever they want to the schema object, which will be handed to any following filters, then used by the producer.
Filters are set as an array, which gives the order they run in. Like parsers and producers, they can be defined by a module name, a module name relative to the SQL::Translator::Filter namespace, a module name and function name together or a reference to an anonymous subroutine. When using a module name a function called filter
will be invoked in that package to do the work.
To pass args to the filter set it as an array ref with the 1st value giving the filter (name or sub) and the rest its args. e.g.
$tr->filters(
sub {
my $schema = shift;
# Do stuff to schema here!
},
DropFKeys,
[ "Names", table => 'lc' ],
[ "Foo", foo => "bar", hello => "world" ],
[ "Filter5" ],
);
Although you normally set them in the constructor, which calls through to filters. i.e.
my $translator = SQL::Translator->new(
...
filters => [
sub { ... },
[ "Names", table => 'lc' ],
],
...
);
See t/36-filters.t for more examples.
Multiple set calls to filters are cumulative with new filters added to the end of the current list.
Returns the filters as a list of array refs, the 1st value being a reference to the filter sub and the rest its args.
show_warnings
Toggles whether to print warnings of name conflicts, identifier mutations, etc. Probably only generated by producers to let the user know when something won't translate very smoothly (e.g., MySQL "enum" fields into Oracle). Accepts a true or false value, returns the current value.
translate
The translate
method calls the subroutine referenced by the parser
data member, then calls any filters
and finally calls the producer
sub routine (these members are described above). It accepts as arguments a number of things, in key => value format, including (potentially) a parser and a producer (they are passed directly to the parser
and producer
methods).
Here is how the parameter list to translate
is parsed:
1 argument means it's the data to be parsed; which could be a string (filename) or a reference to a scalar (a string stored in memory), or a reference to a hash, which is parsed as being more than one argument (see next section).
# Parse the file /path/to/datafile my $output = $tr->translate("/path/to/datafile"); # Parse the data contained in the string $data my $output = $tr->translate(\$data);
More than 1 argument means its a hash of things, and it might be setting a parser, producer, or datasource (this key is named "filename" or "file" if it's a file, or "data" for a SCALAR reference.
# As above, parse /path/to/datafile, but with different producers for my $prod ("MySQL", "XML", "Sybase") { print $tr->translate( producer => $prod, filename => "/path/to/datafile", ); } # The filename hash key could also be: datasource => \$data,
You get the idea.
filename, data
Using the filename
method, the filename of the data to be parsed can be set. This method can be used in conjunction with the data
method, below. If both the filename
and data
methods are invoked as mutators, the data set in the data
method is used.
$tr->filename("/my/data/files/create.sql");
or:
my $create_script = do {
local $/;
open CREATE, "/my/data/files/create.sql" or die $!;
<CREATE>;
};
$tr->data(\$create_script);
filename
takes a string, which is interpreted as a filename. data
takes a reference to a string, which is used as the data to be parsed. If a filename is set, then that file is opened and read when the translate
method is called, as long as the data instance variable is not set.
schema
Returns the SQL::Translator::Schema object.
trace
Turns on/off the tracing option of Parse::RecDescent.
validate
Whether or not to validate the schema object after parsing and before producing.
version
Returns the version of the SQL::Translator release.
AUTHORS
See the included AUTHORS file: http://search.cpan.org/dist/SQL-Translator/AUTHORS
If you would like to contribute to the project, you can send patches to the developers mailing list:
sqlfairy-developers@lists.sourceforge.net
Or send us a message (with your Sourceforge username) asking to be added to the project and what you'd like to contribute.
COPYRIGHT
Copyright 2012 the SQL::Translator authors, as listed in "AUTHORS".
LICENSE
This library is free software and may be distributed under the same terms as Perl 5 itself.
BUGS
Please use http://rt.cpan.org/ for reporting bugs.
PRAISE
If you find this module useful, please use http://cpanratings.perl.org/rate/?distribution=SQL-Translator to rate it.
SEE ALSO
perl, SQL::Translator::Parser, SQL::Translator::Producer, Parse::RecDescent, GD, GraphViz, Text::RecordParser, Class::DBI, XML::Writer.