NAME
DBIx::Wrapper - A wrapper around the DBI
SYNOPSIS
use DBIx::Wrapper;
my $db = DBIx::Wrapper->connect($dsn, $user, $auth, \%attr);
my $db = DBIx::Wrapper->connect($dsn, $user, $auth, \%attr,
{ error_handler => sub { print $DBI::errstr },
debug_handler => sub { print $DBI::errstr },
});
my $db = DBIx::Wrapper->connect_from_config($db_key, $config_file,
{ error_handler => sub { print $DBI::errstr },
debug_handler => sub { print $DBI::errstr },
});
my $dbi_obj = DBI->connect(...)
my $db = DBIx::Wrapper->newFromDBI($dbi_obj);
my $dbi_obj = $db->getDBI;
my $rv = $db->insert($table, { id => 5, val => "myval",
the_date => \"NOW()",
});
my $rv = $db->insert($table, { id => 5, val => "myval",
the_date => $db->command("NOW()"),
});
my $rv = $db->replace($table, \%data);
my $rv = $db->smartReplace($table, \%data)
my $rv = $db->delete($table, \%keys);
my $rv = $db->update($table, \%keys, \%data);
my $rv = $db->smartUpdate($table, \%keys, \%data);
my $row = $db->selectFromHash($table, \%keys, \@cols);
my $row = $db->selectFromHashMulti($table, \%keys, \@cols);
my $val = $db->selectValueFromHash($table, \%keys, $col);
my $vals = $db->selectValueFromHashMulti($table, \%keys, \@cols);
my $rows = $db->selectAll($table, \@cols);
my $row = $db->nativeSelect($query, \@exec_args);
my $loop = $db->nativeSelectExecLoop($query);
foreach my $val (@vals) {
my $row = $loop->next([ $val ]);
}
my $row = $db->nativeSelectWithArrayRef($query, \@exec_args);
my $rows = $db->nativeSelectMulti($query, \@exec_args);
my $rows = $db->nativeSelectMultiOrOne($query, \@exec_args);
my $loop = $db->nativeSelectMultiExecLoop($query)
foreach my $val (@vals) {
my $rows = $loop->next([ $val ]);
}
my $rows = $db->nativeSelectMultiWithArrayRef($query, \@exec_args);
my $hash = $db->nativeSelectMapping($query, \@exec_args);
my $hash = $db->nativeSelectDynaMapping($query, \@cols, \@exec_args);
my $hash = $db->nativeSelectRecordMapping($query, \@exec_args);
my $hash = $db->nativeSelectRecordDynaMapping($query, $col, \@exec_args);
my $val = $db->nativeSelectValue($query, \@exec_args);
my $vals = $db->nativeSelectValuesArray($query, \@exec_args);
my $row = $db->abstractSelect($table, \@fields, \%where, \@order);
my $rows = $db->abstractSelectMulti($table, \@fields, \%where, \@order);
my $loop = $db->nativeSelectLoop($query, @exec_args);
while (my $row = $loop->next) {
my $id = $$row{id};
}
my $rv = $db->nativeQuery($query, @exec_args);
my $loop = $db->nativeQueryLoop("UPDATE my_table SET value=? WHERE id=?");
$loop->next([ 'one', 1]);
$loop->next([ 'two', 2]);
my $id = $db->getLastInsertId;
$db->debugOn(\*FILE_HANDLE);
$db->setNameArg($arg)
$db->commit();
$db->ping();
$db->err();
my $str = $db->to_csv($rows);
my $xml = $db->to_xml($rows);
my $bencoded = $db->bencode($rows);
Attributes
Attributes accessed in DBIx::Wrapper object via hash access are
passed on or retrieved from the underlying DBI object, e.g.,
$dbi_obj->{RaiseError} = 1
Named Placeholders
All native* methods (except for nativeSelectExecLoop) support
named placeholders. That is, instead of using ? as a
placeholder, you can use :name, where name is the name of a key
in the hash passed to the method. To use named placeholders,
pass a hash reference containing the values in place of the
@exec_args argument. E.g.,
my $row = $db->nativeSelect("SELECT * FROM test_table WHERE id=:id", { id => 1 });
:: in the query string gets converted to : so you can include
literal colons in the query. :"var name" and :'var name' are
also supported so you can use variable names containing spaces.
The implementation uses ? as placeholders under the hood so that
quoting is done properly. So if your database driver does not
support placeholders, named placeholders will not help you.
DESCRIPTION
DBIx::Wrapper provides a wrapper around the DBI that makes it a bit
easier on the programmer. This module allows you to execute a query with
a single method call as well as make inserts easier, etc. It also
supports running hooks at various stages of processing a query (see the
section on "Hooks").
METHODS
Following are DBIx::Wrapper methods. Any undocumented methods should be
considered private.
connect($data_source, $username, $auth, \%attr, \%params)
Connects to the given database. The first four parameters are
the same parameters you would pass to the connect call when
using DBI directly. If $data_source is a hash, it will generate
the dsn for DBI using the values for the keys driver, database,
host, port.
The %params hash is optional and contains extra parameters to
control the behaviour of DBIx::Wrapper itself. Following are
the valid parameters.
error_handler and debug_handler
These values should either be a reference to a subroutine, or a
reference to an array whose first element is an object and whose
second element is a method name to call on that object. The
parameters passed to the error_handler callback are the current
DBIx::Wrapper object and an error string, usually the query if
appropriate. The parameters passed to the debug_handler
callback are the current DBIx::Wrapper object, an error string,
and the filehandle passed to the debugOn() method (defaults to
STDERR). E.g.,
sub do_error {
my ($db, $str) = @_;
print $DBI::errstr;
}
sub do_debug {
my ($db, $str, $fh) = @_;
print $fh "query was: $str\n";
}
my $db = DBIx::Wrapper->connect($ds, $un, $auth, \%attr,
{ error_handler => \&do_error,
debug_handler => \&do_debug,
});
db_style
Used to control some database specific logic. The default value
is 'mysql'. Currently, this is only used for the
getLastInsertId() method. MSSQL is supported with a value of
mssql for this parameter.
heavy
If set to a true value, any hashes returned will actually be
objects on which you can call methods to get the values back.
E.g.,
my $row = $db->nativeSelect($query);
my $id = $row->id;
or
my $id = $row->{id};
no_placeholders
If you are unfortunate enough to be using a database that does
not support placeholders, you can set no_placeholders to a true
value here. For non native* methods that generate SQL on their
own, placeholders are normally used to ensure proper quoting of
values. If you set no_placeholders to a true value, DBI's
quote() method will be used to quote the values instead of using
placeholders.
new($data_source, $username, $auth, \%attr, \%params)
An alias for connect().
connect_from_config($db_key, $config_file, \%params)
Like connect(), but the parameters used to connect are taken
from the given configuration file. The Config::General module
must be present for this method to work (it is loaded as
needed). $config_file should be the path to a configuration
file in an Apache-style format. $db_key is the name of the
container with the database connection information you wish to
use. The %params hash is optional and contains extra parameters
to control the behaviour of DBIx::Wrapper itself.
Following is an example configuration file. Note that the dsn
can be specified either as a container with each piece named
separately, or as an option whose value is the full dsn that
should be based to the underlying DBI object. Each db container
specifies one database connection. Note that, unlike Apache,
the containers and option names are case-sensitive.
driver mysql
database test_db
host example.com
port 3306
user test_user
password test_pwd
RaiseError 0
PrintError 1
dsn "dbi:mysql:database=test_db;host=example.com;port=3306"
user test_user
password test_pwd
Configuration features from Config::General supported:
* Perl style comments
* C-style comments
* Here-documents
* Apache style Include directive
* Variable interpolation (see docs for Config::General::Interpolated)
reconnect()
Reconnect to the database using the same parameters that were
given to the connect() method. It does not try to disconnect
before attempting to connect again.
disconnect()
Disconnect from the database. This disconnects and frees up the
underlying DBI object.
connectOne(\@cfg_list, \%attr)
Connects to a random database out of the list. This is useful
for connecting to a slave database out of a group for read-only
access. Ths list should look similar to the following:
my $cfg_list = [ { driver => 'mysql',
host => 'db0.example.com',
port => 3306,
database => 'MyDB',
user => 'dbuser',
auth => 'dbpwd',
attr => { RaiseError => 1 },
weight => 1,
},
{ driver => 'mysql',
host => 'db1.example.com',
port => 3306,
database => 'MyDB',
user => 'dbuser',
auth => 'dbpwd',
attr => { RaiseError => 1 },
weight => 2,
},
];
where the weight fields are optional (defaulting to 1). The
attr field is also optional and corresponds to the 4th argument
to DBI's connect() method. The \%attr passed to this method is
an optional parameter specifying the defaults for \%attr to be
passed to the connect() method. The attr field in the config
for each database in the list overrides any in the \%attr
parameter passed into the method.
You may also pass the DSN string for the connect() method as the
'dsn' field in each config instead of the separate driver, host,
port, and database fields, e.g.,
my $cfg_list = [ { dsn => 'dbi:mysql:host=db0.example.com;database=MyDB;port=3306',
user => 'dbuser',
auth => 'dbpwd',
attr => { RaiseError => 1 },
weight => 1,
},
];
Aliases: connect_one
newFromDBI($dbh)
Returns a new DBIx::Wrapper object from a DBI object that has
already been created. Note that when created this way,
disconnect() will not be called automatically on the underlying
DBI object when the DBIx::Wrapper object goes out of scope.
Aliases: new_from_dbi
getDBI()
Return the underlying DBI object used to query the database.
Aliases: get_dbi, getDbi
insert($table, \%data)
Insert the provided row into the database. $table is the name
of the table you want to insert into. %data is the data you
want to insert -- a hash with key/value pairs representing a row
to be insert into the database.
replace($table, \%data)
Same as insert(), except does a REPLACE instead of an INSERT for
databases which support it.
smartReplace($table, \%data)
This method is MySQL specific. If $table has an auto_increment
column, the return value will be the value of the auto_increment
column. So if that column was specified in \%data, that value
will be returned, otherwise, an insert will be performed and the
value of LAST_INSERT_ID() will be returned. If there is no
auto_increment column, but primary keys are provided, the row
containing the primary keys will be returned. Otherwise, a true
value will be returned upon success.
Aliases: smart_replace
delete($table, \%keys), delete($table, \@keys)
Delete rows from table $table using the key/value pairs in %keys
to specify the WHERE clause of the query. Multiple key/value
pairs are joined with 'AND' in the WHERE clause. The cols
parameter can optionally be an array ref instead of a hashref.
E.g.
$db->delete($table, [ key1 => $val1, key2 => $val2 ])
This is so that the order of the parameters in the WHERE clause
are kept in the same order. This is required to use the correct
multi field indexes in some databases.
update($table, \%keys, \%data), update($table, \@keys, \%data)
Update the table using the key/value pairs in %keys to specify
the WHERE clause of the query. %data contains the new values
for the row(s) in the database. The keys parameter can
optionally be an array ref instead of a hashref. E.g.,
$db->update($table, [ key1 => $val1, key2 => $val2 ], \%data);
This is so that the order of the parameters in the WHERE clause
are kept in the same order. This is required to use the correct
multi field indexes in some databases.
exists($table, \%keys)
Returns true if one or more records exist with the given column
values in %keys. %keys can be recursive as in the
selectFromHash() method.
selectFromHash($table, \%keys, \@cols);
Select from table $table using the key/value pairs in %keys to
specify the WHERE clause of the query. Multiple key/value pairs
are joined with 'AND' in the WHERE clause. Returns a single row
as a hashref. If %keys is empty or not passed, it is treated as
"SELECT * FROM $table" with no WHERE clause. @cols is a list of
columns you want back. If nothing is passed in @cols, all
columns will be returned.
If a value in the %keys hash is an array ref, the resulting
query will search for records with any of those values. E.g.,
my $row = $db->selectFromHash('the_table', { id => [ 5, 6, 7 ] });
will result in a query like
SELECT * FROM the_table WHERE (id=5 OR id=6 OR id=7)
The call
my $row = $db->selectFromHash('the_table', { id => [ 5, 6, 7 ], the_val => 'ten' });
will result in a query like
SELECT * FROM the_table WHERE (id=5 OR id=6 OR id=7) AND the_val="ten"
or, if a value was passed in for \@cols, e.g.,
my $row = $db->selectFromHash('the_table', { id => [ 5, 6, 7 ], the_val => 'ten' }, [ 'id' ]);
the resulting query would be
SELECT id FROM the_table WHERE (id=5 OR id=6 OR id=7) AND the_val="ten"
Aliases: select_from_hash
selectFromHashMulti($table, \%keys, \@cols)
Like selectFromHash(), but returns all rows in the result.
Returns a reference to an array of hashrefs.
Aliases: select_from_hash_multi
selectAll($table, \@cols)
Selects every row in the given table. Equivalent to leaving out
%keys when calling selectFromHashMulti(), e.g.,
$dbh->selectFromHashMulti($table, undef, \@cols). The simplest
case of $dbh->selectAll($table) gets turned into something like
"SELECT * FROM `$table`"
Aliases: select_from_all
selectValueFromHash($table, \%keys, $col)
Combination of nativeSelectValue() and selectFromHash().
Returns the first column from the result of a query given by
$table and %keys, as in selectFromHash(). $col is the column to
return.
selectValueFromHashMulti($table, \%keys, \@cols)
Like selectValueFromhash(), but returns the first column of all
rows in the result.
Aliases: select_value_from_hash_multi
smartUpdate($table, \%keys, \%data)
Same as update(), except that a check is first made to see if
there are any rows matching the data in %keys. If so, update()
is called, otherwise, insert() is called.
Aliases: smart_update
nativeSelect($query, \@exec_args)
Executes the query in $query and returns a single row result (as
a hash ref). If there are multiple rows in the result, the rest
get silently dropped. @exec_args are the same arguments you
would pass to an execute() called on a DBI object. Returns
undef on error.
Aliases: native_select
nativeSelectExecLoop($query)
Like nativeSelect(), but returns a loop object that can be used
to execute the same query over and over with different bind
parameters. This does a single DBI prepare() instead of a new
prepare() for select.
E.g.,
my $loop = $db->nativeSelectExecLoop("SELECT * FROM mytable WHERE id=?");
foreach my $id (@ids) {
my $row = $loop->next([ $id ]);
}
Aliases: native_select_exec_loop
nativeSelectWithArrayRef($query, \@exec_args)
Like nativeSelect(), but return a reference to an array instead
of a hash. Returns undef on error. If there are no results
from the query, a reference to an empty array is returned.
Aliases: native_select_with_array_ref
nativeSelectMulti($query, \@exec_args)
Executes the query in $query and returns an array of rows, where
each row is a hash representing a row of the result. Returns
undef on error. If there are no results for the query, an empty
array ref is returned.
Aliases: native_select_multi
nativeSelectMultiOrOne($query, \@exec_args)
Like nativeSelectMulti(), but if there is only one row in the
result, that row (a hash ref) is returned. If there are zero
rows, undef is returned. Otherwise, an array ref is returned.
Aliases: native_select_multi_or_one
nativeSelectMultiExecLoop($query)
Like nativeSelectExecLoop(), but returns an array of rows, where
each row is a hash representing a row of the result.
Aliases: native_select_multi_exec_loop
nativeSelectMultiWithArrayRef($query, \@exec_args)
Like nativeSelectMulti(), but return a reference to an array of
arrays instead of to an array of hashes. Returns undef on error.
Aliases: native_select_multi_with_array_ref
nativeSelectMapping($query, \@exec_args)
Executes the given query and returns a reference to a hash
containing the first and second columns of the results as
key/value pairs.
Aliases: native_select_mapping
nativeSelectDynaMapping($query, \@cols, \@exec_args)
Similar to nativeSelectMapping() except you specify which
columns to use for the key/value pairs in the return hash. If
the first element of @cols starts with a digit, then @cols is
assumed to contain indexes for the two columns you wish to use.
Otherwise, @cols is assumed to contain the field names for the
two columns you wish to use.
For example,
nativeSelectMapping($query, \@exec_args) is
equivalent (and in fact calls) to
nativeSelectDynaMapping($query, [ 0, 1 ], $exec_args).
Aliases: native_select_dyna_mapping
nativeSelectRecordMapping($query, \@exec_args)
Similar to nativeSelectMapping(), except the values in the hash
are references to the corresponding record (as a hash).
Aliases: native_select_record_mapping
nativeSelectRecordDynaMapping($query, $col, \@exec_args)
Similar to nativeSelectRecordMapping(), except you specify
which column is the key in each key/value pair in the hash. If
$col starts with a digit, then it is assumed to contain the
index for the column you wish to use. Otherwise, $col is
assumed to contain the field name for the two columns you wish
to use.
nativeSelectValue($query, \@exec_args)
Returns a single value, the first column from the first row of
the result. Returns undef on error or if there are no rows in
the result. Note this may be the same value returned for a NULL
value in the result.
Aliases: native_select_value
nativeSelectValuesArray($query, \@exec_args)
Like nativeSelectValue(), but return multiple values, e.g.,
return an array of ids for the query "SELECT id FROM WHERE
color_pref='red'".
Aliases: native_select_values_array
abstractSelect($table, \@fields, \%where, \@order)
Same as nativeSelect() except uses SQL::Abstract to generate the
SQL. See the POD for SQL::Abstract for usage. You must have
SQL::Abstract installed for this method to work.
Aliases: abstract_select
abstractSelectMulti($table, \@fields, \%where, \@order)
Same as nativeSelectMulti() except uses SQL::Abstract to
generate the SQL. See the POD for SQL::Abstract for usage. You
must have SQL::Abstract installed for this method to work.
Aliases: abstract_select_multi
nativeSelectLoop($query, @exec_args)
Executes the query in $query, then returns an object that allows
you to loop through one result at a time, e.g.,
my $loop = $db->nativeSelectLoop("SELECT * FROM my_table");
while (my $row = $loop->next) {
my $id = $$row{id};
}
To get the number of rows selected, you can call the
rowCountCurrent() method on the loop object, e.g.,
my $loop = $db->nativeSelectLoop("SELECT * FROM my_table");
my $rows_in_result = $loop->rowCountCurrent;
The count() method is an alias for rowCountCurrent().
To get the number of rows returned by next() so far, use the
rowCountTotal() method.
Aliases: native_select_loop
nativeQuery($query, \@exec_args, \%attr)
Executes the query in $query and returns true if successful.
This is typically used for deletes and is a catchall for
anything the methods provided by this module don't take into
account.
Aliases: native_query
nativeQueryLoop($query)
A loop on nativeQuery, where any placeholders you have put in
your query are bound each time you call next(). E.g.,
my $loop = $db->nativeQueryLoop("UPDATE my_table SET value=? WHERE id=?");
$loop->next([ 'one', 1]);
$loop->next([ 'two', 2]);
Aliases: native_query_loop
command($cmd_string)
This creates a literal SQL command for use in insert(),
update(), and related methods, since if you simply put something
like "CUR_DATE()" as a value in the %data parameter passed to
insert, the function will get quoted, and so will not work as
expected. Instead, do something like this:
my $data = { file => 'my_document.txt',
the_date => $db->command('CUR_DATE()')
};
$db->insert('my_doc_table', $data);
This can also be done by passing a reference to a string with
the SQL command, e.g.,
my $data = { file => 'my_document.txt',
the_date => \'CUR_DATE()'
};
$db->insert('my_doc_table', $data);
This is currently how command() is implemented.
Aliases: literal, sql_literal
debugOn(\*FILE_HANDLE)
Turns on debugging output. Debugging information will be printed to the
given filehandle.
debugOff()
Turns off debugging output.
setNameArg($arg)
This is the argument to pass to the fetchrow_hashref() call on
the underlying DBI object. By default, this is 'NAME_lc', so
that all field names returned are all lowercase to provide for
portable code. If you want to make all the field names return
be uppercase, call $db->setNameArg('NAME_uc') after the
connect() call. And if you really want the case of the field
names to be what the underlying database driveer returns them
as, call $db->setNameArg('NAME').
Aliases: set_name_arg
err()
Calls err() on the underlying DBI object, which returns the
native database engine error code from the last driver method
called.
errstr()
Calls errstr() on the underlying DBI object, which returns the
native database engine error message from the last driver method
called.
DBI-compatible methods
The following method calls use the same interface as the DBI
method. However, these are not simply passed through to DBI
(see DBI methods below), so any hooks you have defined for
DBIx::Wrapper will be called.
do
DBI methods
The following method calls are just passed through to the
underlying DBI object for convenience. See the documentation
for DBI for details.
prepare
This method may call hooks in the future. Use
prepare_no_hooks() if you want to ensure that it will be a
simple DBI call.
selectrow_arrayref
selectrow_hashref
selectall_arrayref
selectall_hashref
selectcol_arrayref
quote
commit
begin_work
rollback
ping
getLastInsertId(), get_last_insert_id(), last_insert_id()
Returns the last_insert_id. The default is to be MySQL
specific. It just runs the query "SELECT LAST_INSERT_ID()".
However, it will also work with MSSQL with the right parameters
(see the db_style parameter in the section explaining the
connect() method).
Hooks
DBIx::Wrapper supports hooks that get called just before and just after
various query operations. The add*Hook methods take a single argument
that is either a code reference (e.g., anonymous subroutine reference),
or an array whose first element is an object and whose second element is
the name of a method to call on that object.
The hooks will be called with a request object as the first argument.
See DBIx::Wrapper::Request.
The two expected return values are $request->OK and $request->DECLINED.
The first tells DBIx::Wrapper that the current hook has done everything
that needs to be done and doesn't call any other hooks in the stack for
the current request. DECLINED tells DBIx::Wrapper to continue down the
hook stack as if the current handler was never invoked.
See DBIx::Wrapper::Request for example hooks.
addPrePrepareHook($hook)
Specifies a hook to be called just before any SQL statement is
prepare()'d.
addPostPrepareHook($hook)
Specifies a hook to be called just after any SQL statement is
prepare()'d.
addPreExecHook($hook)
Specifies a hook to be called just before any SQL statement is
execute()'d.
addPostExecHook($hook)
Adds a hook to be called just after a statement is execute()'d.
addPreFetchHook($hook)
Adds a hook to be called just before data is fetch()'d from the server.
addPostFetchHook($hook)
Adds a hook to be called just after data is fetch()'d from the server.
Convenience methods
to_csv($rows, \%params);
Convert the given query result rows in @rows to a CSV string.
If each row is a hash, a header row will be included by the
default giving the column names. This method also supports rows
as arrays, as well as $rows itself being a hash ref.
Valid parameters in %params:
sep
The separator to use between columns.
quote
The quote to use in cases where values contain the separator.
If a quote is found in a value, it is converted to two quotes
and then the whole value is quoted.
no_header
If set to a true value, do not output the header row containing
the column names.
Aliases: toCsv()
to_xml($data, \%params)
Converts $data to xml. $data is expected to be either a hash
ref or a reference to an array of hash refs. If $data is an
array ref, enclosing tags are put around each record. The tags
are named "record" by default but can be changed by specifying
record_tag in %params. If $params{indent} is set to a true
value, tags will be indented and unix newlines inserted. This
method does not output an encoding specification, e.g.,
Aliases: toXml()
bencode($data)
Returns the bencoded representation of $data (arbitrary
datastructure -- but not objects). This module extends the
bencode scheme to support undef. See
L for details on the bencode
encoding.
Aliases: bEncode()
bdecode($encoded_str)
The opposite of bencode(). Returns the deserialized data from
the bencoded string.
Aliases: bDecode()
There are also underscore_separated versions of these methods.
E.g., nativeSelectLoop() becomes native_select_loop()
DEPENDENCIES
DBI
ACKNOWLEDGEMENTS
Others who have contributed ideas and/or code for this module:
Kevin Wilson
Mark Stosberg
David Bushong
AUTHOR
Don Owens
LICENSE AND COPYRIGHT
Copyright (c) 2003-2006 Don Owens (don@regexguy.com). All rights
reserved.
This free software; you can redistribute it and/or modify it under the
same terms as Perl itself. See perlartistic.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
SEE ALSO
DBI, perl
VERSION
0.24