| DBIx::Wrapper - A wrapper around the DBI |
reconnect()disconnect()newFromDBI($dbh)getDBI()nativeSelectExecLoop($query)nativeSelectMultiExecLoop($query)nativeQueryLoop($query)command($cmd_string)debugOn(\*FILE_HANDLE)debugOff()setNameArg($arg)err()errstr()last_insert_id()addPrePrepareHook($hook)addPostPrepareHook($hook)addPreExecHook($hook)addPostExecHook($hook)addPreFetchHook($hook)addPostFetchHook($hook)bencode($data)bdecode($encoded_str)to_json($data)
DBIx::Wrapper - A wrapper around the DBI
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 accessed in DBIx::Wrapper object via hash access are passed on or retrieved from the underlying DBI object, e.g.,
$dbi_obj->{RaiseError} = 1
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.
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 L</Hooks>).
Following are DBIx::Wrapper methods. Any undocumented methods should be considered private.
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.
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,
});
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.
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};
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.
An alias for connect().
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.
<db test_db_key>
<dsn>
driver mysql
database test_db
host example.com
port 3306
</dsn>
user test_user
password test_pwd
<attributes>
RaiseError 0
PrintError 1
</attributes>
</db>
<db test_db_key2>
dsn "dbi:mysql:database=test_db;host=example.com;port=3306"
user test_user
password test_pwd
</db>
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.
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 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.
Same as insert(), except does a REPLACE instead of an INSERT for databases which support it.
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 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 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.
Returns true if one or more records exist with the given column values in %keys. %keys can be recursive as in the selectFromHash() method.
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, sfh
Like selectFromHash(), but returns all rows in the result. Returns a reference to an array of hashrefs.
Aliases: select_from_hash_multi, sfhm
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
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.
Aliases: select_value_from_hash, svfh
Like selectValueFromhash(), but returns the first column of all rows in the result.
Aliases: select_value_from_hash_multi, svfhm
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
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
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, nswar
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
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
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
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, nsm
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, nsdm
Similar to nativeSelectMapping(), except the values in the hash are references to the corresponding record (as a hash).
Aliases: native_select_record_mapping
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.
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
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
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
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
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
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.
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.
The following method calls are just passed through to the underlying DBI object for convenience. See the documentation for DBI for details.
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.
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).
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 the DBIx::Wrapper::Request manpage.
The two expected return values are $request->OK and $request->DECLINED. The first tells DBIx::Wrapper that the current hook has done everything that needs to be done and doesn't call any other hooks in the stack for the current request. DECLINED tells DBIx::Wrapper to continue down the hook stack as if the current handler was never invoked.
See the DBIx::Wrapper::Request manpage for example hooks.
addPrePrepareHook($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.
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:
The separator to use between columns.
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.
If set to a true value, do not output the header row containing the column names.
Aliases: toCsv()
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 $params{indent} is set to a true
value, tags will be indented and unix newlines inserted. This
method does not output an encoding specification, e.g.,
<?xml version="1.0" encoding="utf-8"?>
Aliases: toXml()
bencode($data)Returns the bencoded representation of $data (arbitrary datastructure -- but not objects). This module extends the bencode scheme to support undef. See L<http://en.wikipedia.org/wiki/Bencode>; for details on the bencode encoding.
Aliases: bEncode()
bdecode($encoded_str)The opposite of bencode(). Returns the deserialized data from the bencoded string.
Aliases: bDecode()
to_json($data)Returns the JSON representation of $data (arbitrary datastructure -- but not objects). See http://www.json.org/ or http://en.wikipedia.org/wiki/JSON for details. In this implementation, hash keys are sorted so that the output is consistent.
E.g., nativeSelectLoop() becomes native_select_loop()
DBI
Others who have contributed ideas and/or code for this module:
Kevin Wilson
Mark Stosberg
David Bushong
Don Owens <don@regexguy.com>
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.
DBI, perl
0.25
| DBIx::Wrapper - A wrapper around the DBI |