/ 
DBD-Wire10-1.02
River stage zero No dependents
/ DBD::Wire10

NAME

DBD::Wire10 - Pure Perl MySQL, Sphinx, and Drizzle driver for DBI.

DESCRIPTION

DBD::Wire10 is a Pure Perl interface able to connect to MySQL, Sphinx and Drizzle servers, utilizing Net::Wire10 for the actual driver core.

SYNOPSIS

use DBI;

$drh = DBI->install_driver("wire10");

$dsn = "DBI:Wire10:database=$database;host=$host";

$dbh = DBI->connect($dsn, $user, $password);

$sth = $dbh->prepare("SELECT * FROM foo WHERE bar=1");
$sth->execute;
$numCols = $sth->{NUM_OF_FIELDS};
$numRows = $sth->{wire10_selectedrows};
$sth->finish;

$sth = $dbh->prepare("UPDATE foo SET bar=0 WHERE bar=1");
$sth->execute;
$numRows = $sth->rows;
$sth->finish;

INSTALLATION

DBD::Wire10 is installed like any other CPAN module:

$ perl -MCPAN -e shell
cpan> install DBD::Wire10

For Perl installations where the CPAN module (used above) is missing, you can also just download the .tar.gz from this site and drop the DBD folder in the same folder as the Perl file you want to use the connector from.

Some (particularly commercial) Perl distributions may have their own package management systems. Refer to the documentation that comes with your particular Perl distribution for details.

USAGE

From Perl you just need to make use of DBI to get started:

use DBI;

After that you can connect to servers and send queries via a simple object oriented interface. Two types of objects are mainly used: database handles and statement handles. DBI returns a database handle via the connect() method.

Example: connect

use DBI;

my $host = 'localhost';
my $user = 'test';
my $password = 'test';

# Connect to the database server on 'localhost'.
my $dbh = DBI->connect(
  "DBI:Wire10:host=$host",
  $user, $password,
  {RaiseError' => 1, 'AutoCommit' => 1}
);

Example: create table

# Drop table 'foo'. This may fail, if 'foo' doesn't exist.
# Thus we put an eval around it.
eval { $dbh->do("DROP TABLE foo") };
print "Dropping foo failed: $@\n" if $@;

# Create a new table 'foo'. If this fails, we don't want to
# continue, thus we don't catch errors.
$dbh->do("CREATE TABLE foo (id INTEGER, name VARCHAR(20))");

Example: insert data

# INSERT some data into 'foo'. We are using $dbh->quote() for
# quoting the name.
$dbh->do("INSERT INTO foo VALUES (1, " . $dbh->quote("Tim") . ")");

# Same thing, but using placeholders
$dbh->do("INSERT INTO foo VALUES (?, ?)", undef, 2, "Jochen");

Example: retrieve data

# Now retrieve data from the table.
my $sth = $dbh->prepare("SELECT id, name FROM foo");
$sth->execute();
while (my $ref = $sth->fetchrow_arrayref()) {
  print "Found a row: id = $ref->[0], name = $ref->[1]\n";
}
$sth->finish();

Example: disconnect

# Disconnect from the database server.
$dbh->disconnect();

FEATURES

The following DBI features are supported.

Features in DBD::Wire10

Driver factory: methods

Methods available from the DBD::Wire10 driver factory.

driver (internal)

Creates a new driver.

CLONE (internal)

Helper that decouples non-shareable driver internals when the application needs to create a new process using fork().

Features in DBD::Wire10::dr

Driver: methods

connect

Creates a new driver core and dbh object, returns the dbh object.

A DSN is specified in the usual format and connect() is called via DBI:

my $dsn = "DBI:Wire10:database=$database;host=$host;port=$port";
my $options = {'RaiseError'=>1, 'Warn'=>1};
my $dbh = DBI->connect($dsn, $user, $password, $options);

The default port numbers are 3306 for MySQL Server, 3307 for Sphinx and 4427 for Drizzle. Some server types support multiple protocols, in which case they may also listen on other, unrelated ports.

wire10_debug can be specified in the attribute hash for very noise debug output. It is a bitmask, where 1 shows normal debug messages, 2 shows messages flowing back and forth between client and server, and 4 shows raw TCP traffic.

wire10_timeout can be specified in the attribute hash to set a connect and query timeout. Otherwise, the driver's default values are used.

Warn can be specified to 1 in the attribute hash to output warnings when some silly things are attempted.

RaiseError can be specified to 1 in the attribute hash to enable error handling. Use eval { ... }; guard blocks to catch errors. After the guard block, the special variable $@ is either undefined or contains an error message.

PrintError can be specified to 1 in the attribute hash to disable error handling, and instead print a line on the console and continue execution whenever an error happens.

data_sources

Implemented, but does not return a list of databases, just a blank entry with the name of the driver.

Features in DBD::Wire10::db

Database server connection: methods

Some methods have default implementations in DBI, those are not listed here. Refer also to the DBI::DBI documentation.

quote

Quotes a string literal.

MySQL Server chokes if you give it LIMIT parameters that are properly quoted. To work around this, the quote() method specifically does not quote purely numerical values. To quote all values, including numerical values, use Net::Wire10::Util::quote().

quote_identifier

Quotes a schema identifier such as database or table names.

prepare

Given an SQL string, prepares a statement for executing.

Question marks (?) can be used in place of parameters. Actual parameters can then be added later either with a call to bind_param(), or when calling execute().

get_info

Returns various information about the database server when given a code for the particular information to retrieve.

commit

Commits the active transaction.

rollback

Rolls back the active transaction.

disconnect

Disconnects from the database server.

ping

Sends a ping over the network protocol. An error is reported via the standard DBI error mechanism if this fails.

reconnect

Makes sure that there is a connection to the database server. If there is no connection, and the attempt to reconnect fails, an error is reported via the standard DBI error reporting mechanism.

Notice that the timeout when calling this method is in a sense doubled. reconnect() first performs a ping() if the connection seems to be alive. If the ping fails after timeout seconds, then a new underlying connection is established, and establishing this connection could last an additional timeout seconds.

err

Contains an error code when an error has happened. Always use RaiseError and eval {} to catch errors in production code.

state

Contains an SQLSTATE code when an error has happened.

errstr

Contains an error message when an error has happened. Always use RaiseError and eval {} to catch errors in production code.

STORE (internal)

Used internally to store attributes.

FETCH (internal)

Used internally to fetch attributes.

DESTROY (internal)

Used internally to destroy the object.

Database server connection: attributes

Some attributes have default implementations in DBI, those are not listed here. Refer also to the DBI::DBI documentation.

AutoCommit

Enables or disables automatic commit after each query, in effect wrapping each query in an implicit transaction.

Warn

If enabled, warnings are emitted when unexpected things might occur.

wire10_timeout

The timeout, in seconds, before the driver stops waiting for data from the network when executing a command or connecting to a server.

wire10_thread_id

Returns the connection id of the current connection on the server.

wire10_server_version

Returns the server version of the currently connected-to server.

wire10_debug

A debug bitmask, which when enabled will spew a lots of messages to the console. 1 shows normal debug messages, 2 shows messages flowing back and forth between client and server, and 4 shows raw TCP traffic.

wire10_insertid (imposed by sth->execute)

Contains the auto_increment value for the last row inserted. Always use $sth->{wire10_insertid} instead, if the $sth object is available, since this value can be overwritten by irrelevant transactions.

Potentially useful for single-threaded applications that make use of DBI commands which does not return $sth objects, such as do().

wire10_selectedrows (imposed by sth->execute)

Contains the number of rows returned in the last result set. Always use $sth->{wire10_selectedrows} instead, if the $sth object is available, since this value can be overwritten by irrelevant transactions.

wire10_warning_count (imposed by sth->execute)

Contains the number of warnings produced by the last query. Always use $sth->{wire10_warning_count} instead, if the $sth object is available, since this value can be overwritten by irrelevant transactions.

Active (internal)

Used internally to notify DBI that connect() has been called and disconnect() has not.

wire10_driver_dbh (internal)

This is the internal handle for the core driver object associated with the DBI connection.

wire10_autocommit (internal)

Used internally to store the current AutoCommit setting.

Features in DBD::Wire10::st

Statement: methods

bind_param

Given an index and a value, binds that value to the parameter at the given index in the prepared statement. Use after prepare() and before execute().

To bind binary data to a parameter, specify a type such as SQL_BLOB. This prevents the data from being considered Latin-1 or Unicode text. Example:

$sth->bind_param(1, $mydata, SQL_BLOB);

Parameters are numbered beginning from 1.

execute

Runs a prepared statement, optionally using parameters. Parameters are supplied either via bind_param(), or directly in the call to execute(). When parameters are given in the call to execute(), they override earlier bound parameters for the duration of the call.

cancel

Cancels the currently executing command (query or ping). Safe to call from another thread, but note that DBI currently prevents this.

Non-threaded approaches to invoking cancel() such as SIGALRM is generally unsupported by Windows distributions of Perl, so the above affects that query cancelling is only supported on Unix. A workaround (for this DBD driver) is to grab a reference to the internal driver core and call cancel() on that instead.

Use cancel for interactive code only, where a user may cancel an operation at any time. Do not use cancel for setting query timeouts. For that, use the timeout property instead. The timeout property has slightly better performance, because it does not precipitate creation of an extra thread.

Always returns 1 (success). The actual status of the query (finished or cancelled, depending on timing) appears in the thread which is running the actual query.

The driver core fetches all results in execute(), so cancelling later on during a fetch does nothing to the current statement.

If a cancel happens to be performed after the current command has finished executing, it will instead take effect during the next command. In that case, the cancel can be forced out of the system with a ping(), or a reconnect() which implicitly does a ping().

finish

Clears out the resources used by a statement. This is called automatically at the start of a new query, among other places, and is therefore normally not necessary to call explicitly.

fetchrow_arrayref

Fetch one row as an array.

fetch

Deprecated alias for fetchrow_arrayref.

rows

The number of affected rows after an UPDATE or similar query, or the number of rows so far read by the client during a SELECT or similar query.

STORE (internal)

Used internally to store attributes.

FETCH (internal)

Used internally to fetch attributes.

DESTROY (internal)

Used internally to destroy the object.

Statement: attributes

wire10_insertid

Contains the auto_increment value for the last row inserted.

my $id = $sth->{wire10_insertid};

wire10_selectedrows

Contains the number of rows returned in the last result set.

my $numRows = $sth->{wire10_selectedrows};

wire10_warning_count

Contains the number of warnings produced by the last query.

my $warnings = $sth->{wire10_warning_count};

ChopBlanks

If enabled, runs every field value in result sets through a regular expression that trims for whitespace.

NUM_OF_PARAMS

Returns the number of parameter tokens found in the prepared statement after a prepare().

NUM_OF_FIELDS

Returns the number of columns in the result set after a query has been executed.

my $numCols = $sth->{NUM_OF_FIELDS};

NAME

Returns the names of all the columns in the result set after a query has been executed.

Active (internal)

Used internally to notify DBI that the statement has an active result iterator.

wire10_driver_sth (internal)

Used internally to store a reference to the core driver object.

wire10_iterator (internal)

Used internally to store a reference to the active result iterator, if any.

wire10_prepared (internal)

Used internally to store a reference to the prepared statement created by the core driver.

wire10_rows (internal)

Used internally to store the number of affected rows.

TROUBLESHOOTING

Supported operating systems and Perl versions

This module has been tested on these OSes.

  • Windows Server 2008

    with ActivePerl 5.10.0 build 1004, 32 and 64-bit

Unsupported features

DBI has a rich set of reference features, some of which are not implemented by each individual driver.

In general, it should be possible to check for particular features before using them with the can() method, available on all types of DBI handles, and raise an error if a required feature is not supported.

Here is a list of some notable features that this driver does not have.

See also the documentation for "Unsupported features" in Net::Wire10 for limitations in the driver core.

Unsupported database server connection features in DBD::Wire10::db

The following methods are supposed to be implemented by the DBD connection, but is not (yet) supported in this driver. For an up-to-date list, see the DBI documentation.

  • type_info_all

  • type_info

  • table_info (and tables)

    @names = $dbh->tables;

    Should return a list of table and view names, possibly including a schema prefix. This list should include all tables that can be used in a "SELECT" statement without further qualification.

  • column_info

  • primary_key_info (and primary_key)

  • foreign_key_info

  • statistics_info

  • list_tables

  • last_insert_id

  • take_imp_data

The following attributes are supposed to be implemented by each DBD driver, but is not (yet) supported in this driver. For an up-to-date list, see the DBI documentation.

  • Name

  • RowCacheSize

  • LongReadLen

  • LongTruncOk

Unsupported statement features in DBD::Wire10::st

The following methods are supposed to be implemented by each DBD driver, but is not (yet) supported in this driver. For an up-to-date list, see the DBI documentation.

  • bind_col

  • bind_columns

  • bind_param_inout

The following attributes are supposed to be implemented by each DBD driver, but is not (yet) supported in this driver. For an up-to-date list, see the DBI documentation.

  • TYPE

  • PRECISION

  • SCALE

  • NULLABLE

  • CursorName

  • RowsInCache

  • ParamValues

  • ParamArrays

  • ParamTypes

Return value of execute('SELECT * from something')

DBD::Wire10 returns true on success, and false on failure, as specified in DBI documentation. This differs from DBD::mysql, which returns the number of selected rows.

To get the number of rows from a SELECT statement, use this:

my $numRows = $sth->{wire10_selectedrows};

If streaming is turned on in the DBD driver (by switching internally from query() to stream()), the above functionality would be disabled, and -1 would be returned every time.

The wire protocol does not have any means by which the server can tell the client how many rows are in the result set, even if the server should discover this at some point. Therefore the row count is only available after the entire result set has been pulled down to the client.

Using tokens for LIMITs in prepared statements

MySQL Server chokes if you give it LIMIT parameters that are properly quoted. As a workaround, this DBD driver scans all field values given to it, and when a purely numerical value is found, it is not quoted.

Dependencies

This module requires these other modules and libraries:

L<DBI::DBI>
L<Net::Wire10>

Net::Wire10 is a Pure Perl connector for MySQL, Sphinx and Drizzle servers.

Net::Wire10 implements the network protool used to communicate between server and client.

SEE ALSO

DBI::FAQ DBI::DBI Net::Wire10

AUTHORS

DSN parsing and various code by Hiroyuki OYAMA E, Japan. DBD boilerplate by DBD authors. Various code by the open source team at Dubex A/S.

COPYRIGHT AND LICENCE

Copyright (C) 2002 and (C) 2009 as described in AUTHORS.

This is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

WARRANTY

Because this software is licensed free of charge, there is absolutely no warranty of any kind, expressed or implied.