DBIx::Simple(3) User Contributed Perl Documentation DBIx::Simple(3)NAMEDBIx::Simple - Easy-to-use OO interface to DBI
SYNOPSISDBIx::Simple
$db = DBIx::Simple->connect(...) # or ->new
$db->keep_statements = 16
$db->lc_columns = 1
$db->result_class = 'DBIx::Simple::Result';
$db->begin_work $db->commit
$db->rollback $db->disconnect
$db->func(...) $db->last_insert_id
$result = $db->query(...)
DBIx::SImple + SQL::Interp
$result = $db->iquery(...)
DBIx::Simple + SQL::Abstract
$db->abstract = SQL::Abstract->new(...)
$result = $db->select(...)
$result = $db->insert(...)
$result = $db->update(...)
$result = $db->delete(...)
DBIx::Simple::Result
@columns = $result->columns
$result->into($foo, $bar, $baz)
$row = $result->fetch
@row = $result->list @rows = $result->flat
$row = $result->array @rows = $result->arrays
$row = $result->hash @rows = $result->hashes
%map = $result->map_arrays(...)
%map = $result->map_hashes(...)
%map = $result->map
$rows = $result->rows
$dump = $result->text
$result->finish
DBIx::Simple::Result + DBIx::XHTML_Table
$html = $result->html(...)
$table_object = $result->xto(...)
Examples
Please read DBIx::Simple::Examples for code examples.
DESCRIPTIONDBIx::Simple provides a simplified interface to DBI, Perl's powerful
database module.
This module is aimed at rapid development and easy maintenance. Query
preparation and execution are combined in a single method, the result
object (which is a wrapper around the statement handle) provides easy
row-by-row and slurping methods.
The "query" method returns either a result object, or a dummy object.
The dummy object returns undef (or an empty list) for all methods and
when used in boolean context, is false. The dummy object lets you
postpone (or skip) error checking, but it also makes immediate error
checking simply "$db->query(...) or die $db->error".
DBIx::Simple methods
"DBIx::Simple->connect($dbh)"
"DBIx::Simple->connect($dsn, $user, $pass, \%options)"
"DBIx::Simple->new($dbh)"
"DBIx::Simple->new($dsn, $user, $pass, \%options)"
The "connect" or "new" class method takes either an existing DBI
object ($dbh), or a list of arguments to pass to "DBI->connect".
See DBI for a detailed description.
You cannot use this method to clone a DBIx::Simple object: the $dbh
passed should be a DBI::db object, not a DBIx::Simple object.
This method is the constructor and returns a DBIx::Simple object on
success. On failure, it returns undef.
"lc_columns = $bool"
When true at time of query execution, makes "columns", "hash",
"hashes", and "map_hashes" use lower cased column names.
"lc_columns" is true by default.
"keep_statements = $integer"
Sets the number of statement objects that DBIx::Simple can keep for
reuse. This can dramatically speed up repeated queries (like when
used in a loop). "keep_statements" is 16 by default.
A query is only reused if it equals a previously used one
literally. This means that to benefit from this caching mechanism,
you must use placeholders and never interpolate variables yourself.
# Wrong:
$db->query("INSERT INTO foo VALUES ('$foo', '$bar', '$baz')");
$db->query("SELECT FROM foo WHERE foo = '$foo' OR bar = '$bar'");
# Right:
$db->query('INSERT INTO foo VALUES (??)', $foo, $bar, $baz);
$db->query('SELECT FROM foo WHERE foo = ? OR bar = ?', $foo, $baz);
Of course, automatic value escaping is a much better reason for
using placeholders.
"result_class = $string"
Class to use for result objects. Defaults to DBIx::Simple::Result.
A constructor is not used.
"error"
Returns the error string of the last DBI method. See the discussion
of ""err"" and ""errstr"" in DBI.
"query($query, @values)"
The "query" method prepares and executes the query and returns a
result object.
If the string "(??)" is present in the query, it is replaced with a
list of as many question marks as @values.
The database drivers substitute placeholders (question marks that
do not appear in quoted literals) in the query with the given
@values, after them escaping them. You should always use
placeholders, and never use raw user input in database queries.
On success, returns a DBIx::Simple::Result object.
On failure, returns a DBIx::Simple::Dummy object.
"iquery"
Uses SQL::Interp to interpolate values into a query, and uses the
resulting generated query and bind arguments with "query".
See SQL::Interp's documentation for usage information.
Requires that Mark Stosberg's SQL::Interp module be installed. It
is available from CPAN. SQL::Interp is a fork from David Manura's
SQL::Interpolate.
"select", "insert", "update", "delete"
Calls the respective method on "abstract", and uses the resulting
generated query and bind arguments with "query".
See SQL::Abstract's documentation for usage information. You can
override the object by assigning to the "abstract" property.
Obviously, calling "query" directly is faster for the computer and
using these abstracting methods is faster for the programmer.
"abstract = SQL::Abstract->new(...)"
Sets the object to use with the "select", "insert", "update" and
"delete" methods. On first access, will create one with
SQL::Abstract's default options.
Requires that Nathan Wiger's SQL::Abstract module be installed. It
is available from CPAN.
In theory, you can assign any object to this property, as long as
that object has these four methods, and they return a list suitable
for use with the "query" method.
"begin_work", "begin", "commit", "rollback"
These transaction related methods call the DBI respective methods
and Do What You Mean. See DBI for details.
"begin" is an alias for "begin_work".
"func(...)"
This calls the "func" method of DBI. See DBI for details.
"last_insert_id(...)"
This calls the "last_insert_id" method of DBI. See DBI for details.
Note that this feature requires DBI 1.38 or newer.
"dbh"
Exposes the internal database handle. Use this only if you know
what you are doing. Keeping a reference or doing queries can
interfere with DBIx::Simple's garbage collection and error
reporting.
"disconnect"
Destroys (finishes) active statements and disconnects. Whenever the
database object is destroyed, this happens automatically if
DBIx::Simple handled the connection (i.e. you didn't use an
existing DBI handle). After disconnecting, you can no longer use
the database object or any of its result objects.
DBIx::Simple::Dummy
The "query" method of DBIx::Simple returns a dummy object on failure.
Its methods all return an empty list or undef, depending on context.
When used in boolean context, a dummy object evaluates to false.
DBIx::Simple::Result methods
"columns" Returns a list of column names. In scalar context, returns
an array reference.
Column names are lower cased if "lc_columns" was true when
the query was executed.
"bind(LIST)"
Binds the given LIST to the columns. The elements of LIST
must be writable LVALUEs. In other words, use this method
as:
$result->bind(my ($foo, $bar));
$result->fetch;
Or, combined:
$result->into(my ($foo, $bar));
Unlike with DBI's "bind_columns", the "\" operator is not
needed.
Bound variables are very efficient. Binding a tied variable
doesn't work.
"fetch" Fetches a single row and returns a reference to the array
that holds the values. This is the same array every time.
Subsequent fetches (using any method) may change the values
in the variables passed and the returned reference's array.
"into(LIST)"
Combines "bind" with "fetch". Returns what "fetch" returns.
"list" Fetches a single row and returns a list of values. In
scalar context, returns only the last value.
"array" Fetches a single row and returns an array reference.
"hash" Fetches a single row and returns a hash reference.
Keys are lower cased if "lc_columns" was true when the
query was executed.
"flat" Fetches all remaining rows and returns a flattened list.
In scalar context, returns an array reference.
"arrays" Fetches all remaining rows and returns a list of array
references.
In scalar context, returns an array reference.
"hashes" Fetches all remaining rows and returns a list of hash
references.
In scalar context, returns an array reference.
Keys are lower cased if "lc_columns" was true when the
query was executed.
"map_arrays($column_number)"
Constructs a hash of array references keyed by the values
in the chosen column.
In scalar context, returns a hash reference.
In list context, returns interleaved keys and values.
"map_hashes($column_name)"
Constructs a hash of hash references keyed by the values in
the chosen column.
In scalar context, returns a hash reference.
In list context, returns interleaved keys and values.
"map" Constructs a simple hash, using the two columns as
key/value pairs. Should only be used with queries that
return two columns.
In scalar context, returns a hash reference.
In list context, returns interleaved keys and values.
"rows" Returns the number of rows affected by the last row
affecting command, or -1 if the number of rows is not known
or not available.
For SELECT statements, it is generally not possible to know
how many rows are returned. MySQL does provide this
information. See DBI for a detailed explanation.
"xto(%attr)"
Returns a DBIx::XHTML_Table object, passing the constructor
a reference to %attr.
Requires that Jeffrey Hayes Anderson's DBIx::XHTML_Table
module be installed. It is available from CPAN.
In general, using the "html" method (described below) is
much easier. "xto" is available in case you need more
flexibility.
This method ignores the "lc_columns" property.
"html(%attr)"
Returns an (X)HTML formatted table, using the
DBIx::XHTML_Table module. Passes a reference to %attr to
both the constructor and the "output" method.
Requires that Jeffrey Hayes Anderson's DBIx::XHTML_Table
module be installed. It is available from CPAN.
This method is a shortcut method. That means that
$result->html
$result->html(
tr => { bgcolor => [ 'silver', 'white' ] },
no_ucfirst => 1
)
do the same as:
$result->xto->output
$result->xto(
tr => { bgcolor => [ 'silver', 'white' ] }
)->output(
no_ucfirst => 1
);
"text($type)"
Returns a string with a simple text representation of the
data. $type can be any of: "neat", "table", "box". It
defaults to "table" if Text::Table is installed, to "neat"
if it is.
"table" and "box" require that Anno Siegel's Text::Table
module be installed. It is available from CPAN.
"attr(...)" Returns a copy of an sth attribute (property). See
"Statement Handle Attributes" in DBI for details.
"func(...)" This calls the "func" method of DBI. See DBI for details.
"finish" Finishes the statement. After finishing a statement, it can
no longer be used. When the result object is destroyed,
its statement handle is automatically finished and
destroyed. There should be no reason to call this method
explicitly; just let the result object go out of scope.
MISCELLANEOUS
The mapping methods do not check whether the keys are unique. Rows that
are fetched later overwrite earlier ones.
PrintError is disabled by default. If you enable it, beware that it
will report line numbers in DBIx/Simple.pm.
LICENSE
There is no license. This software was released into the public domain.
Do with it what you want, but on your own risk. The author disclaims
any responsibility.
AUTHOR
Juerd Waalboer <juerd@cpan.org> <http://juerd.nl/>
SEE ALSO
perl, perlref
DBI, DBIx::Simple::Examples, SQL::Abstract, DBIx::XHTML_Table
perl v5.10.1 2007-09-17 DBIx::Simple(3)