LXXIII. MaxDB PHP Extension

Introduction

The MaxDB PHP extension allows you to access the functionality provided by MaxDB 7.5.0 and above. More information about the MaxDB Database server can be found at http://www.mysql.com/products/maxdb/.

The MaxDB PHP extension is compatible to the MySQL mysqli extension. There are only minor differences in the behaviour of some functions due to the differences of the underlying database servers, MaxDB and MySQL.

The main differences to mysqli are in the following functions:

maxdb_character_set_name() - Returns only ascii or unicode.
maxdb_get_client_info() - Returns a different version string.
maxdb_get_client_version() - Returns a different version string.
maxdb_get_host_info() - Returns localhost or hostname.
maxdb_get_server_info() - Returns a different version string.
maxdb_get_server_version() - Returns a different version string.
maxdb_kill() - Only disconnects the session.
maxdb_multi_query() - Can not handle multiple SQL statements.
maxdb_next_result() - Function returns always false.
maxdb_options() - Supports a different set of options.
maxdb_report() - Supports a different report mode.
maxdb_stat() - Returns a different system status string.
maxdb_stmt_store_result() - Is not necessary for MaxDB.
maxdb_store_result() - Is not necessary for MaxDB.

Documentation for MaxDB can be found at http://dev.mysql.com/doc/maxdb/.

Requirements

In order to have these functions available, you must compile PHP with MaxDB support. Additionally, you must have the MaxDB SQLDBC runtime library available to access the MaxDB server.

Documentation for MaxDB SQLDBC can be found at http://dev.mysql.com/doc/maxdb/.

Download the MaxDB SQLDBC package from http://dev.mysql.com/downloads/maxdb/clients.html.

Installation

By using the --with-maxdb[=DIR] configuration option you enable PHP to access MaxDB databases. [DIR] points to the directory that contains the installed MaxDB SQLDBC package.

Windows users will need to enable php_maxdb.dll inside of php.ini.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. MaxDB Configuration Options

NameDefaultChangeableChangelog
maxdb.default_hostNULLPHP_INI_ALL 
maxdb.default_dbNULLPHP_INI_ALL 
maxdb.default_userNULLPHP_INI_ALL 
maxdb.default_pwNULLPHP_INI_ALL 
maxdb.long_readlen"200"PHP_INI_ALL 
For further details and definitions of the PHP_INI_* constants, see the Appendix G.

Here's a short explanation of the configuration directives.

maxdb.default_host string

The default server host to use when connecting to the database server if no other host is specified.

maxdb.default_db string

The default server database to use when connecting if no other database is specified.

maxdb.default_user string

The default user name to use when connecting to the database server if no other name is specified.

maxdb.default_pw string

The default password to use when connecting to the database server if no other password is specified.

maxdb.long_readlen integer

The default maximum length of bytes that is transferred to the client if long data is retrieved from the MaxDB database server.

Predefined Classes

maxdb

Represents a connection between PHP and a MaxDB database.

Constructor

  • maxdb - construct a new maxdb object

Methods

  • autocommit - turns on or off auto-commiting database modifications

  • change_user - changes the user of the specified database connection

  • character_set_name - returns the default character set for the database connection

  • close - closes a previously opened connection

  • commit - commits the current transaction

  • connect - opens a new connection to MaxDB database server

  • debug - performs debugging operations

  • dump_debug_info - dumps debug information

  • get_client_info - returns client version

  • get_host_info - returns type of connection used

  • get_server_info - returns version of the MaxDB server

  • get_server_version - returns version of the MaxDB server

  • init - initializes maxdb object

  • info - retrieves information about the most recently executed query

  • kill - asks the server to kill a MaxDB thread

  • multi_query - performs multiple queries

  • more_results - check if more results exist from currently executed multi-query

  • next_result - reads next result from currently executed multi-query

  • options - set options

  • ping - pings a server connection or reconnects if there is no connection

  • prepare - prepares a SQL query

  • query - performs a query

  • real_connect - attempts to open a connection to MaxDB database server

  • escape_string - escapes special characters in a string for use in a SQL statement, taking into account the current charset of the connection

  • rollback - rolls back the current transaction

  • select_db - selects the default database

  • ssl_set - sets ssl parameters

  • stat - gets the current system status

  • stmt_init- initializes a statement for use with maxdb_stmt_prepare

  • store_result - transfers a resultset from last query

  • use_result - transfers an unbuffered resultset from last query

  • thread-safe - returns whether thread safety is given or not

Properties

  • affected_rows - gets the number of affected rows in a previous MaxDB operation

  • client_info - returns the MaxDB client version as a string

  • client_version - returns the MaxDB client version as an integer

  • errno - returns the error code for the most recent function call

  • error - returns the error string for the most recent function call

  • field_count - returns the number of columns for the most recent query

  • host_info - returns a string representing the type of connection used

  • info - retrieves information about the most recently executed query

  • insert_id - returns the auto generated id used in the last query

  • protocol_version - returns the version of the MaxDB protocol used

  • sqlstate - returns a string containing the SQLSTATE error code for the last error

  • thread_id - returns the thread ID for the current connection

  • warning_count - returns the number of warnings generated during execution of the previous SQL statement

maxdb_stmt

Represents a prepared statement.

Methods

  • bind_param - binds variables to a prepared statement

  • bind_result - binds variables to a prepared statement for result storage

  • close - closes a prepared statement

  • data-seek - seeks to an arbitrary row in a statement result set

  • execute - executes a prepared statement

  • fetch - fetches result from a prepared statement into bound variables

  • free_result - frees stored result memory for the given statement handle

  • result_metadata - retrieves a resultset from a prepared statement for metadata information

  • prepare - prepares a SQL query

  • send_long_data - sends data in chunks

  • close_long_data - end sending long data

  • reset - resets a prepared statement

  • store_result - buffers complete resultset from a prepared statement

Properties

  • affected_rows - returns affected rows from last statement execution

  • errno - returns errorcode for last statement function

  • errno - returns errormessage for last statement function

  • param_count - returns number of parameter for a given prepare statement

  • sqlstate - returns a string containing the SQLSTATE error code for the last statement function

maxdb_result

Represents the result set obtained from a query against the database.

Methods

  • close - closes resultset

  • data_seek - moves internal result pointer

  • fetch_field - gets column information from a resultset

  • fetch_fields - gets information for all columns from a resulset

  • fetch_field_direct - gets column information for specified column

  • fetch_array - fetches a result row as an associative array, a numeric array, or both.

  • fetch_assoc - fetches a result row as an associative array

  • fetch_object - fetches a result row as an object

  • fetch_row - gets a result row as an enumerated array

  • close - frees result memory

  • field_seek - set result pointer to a specified field offset

Properties

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

The following constants to use with maxdb_options() are defined. For further description of these constants see http://dev.mysql.com/doc/maxdb/.

Table 2. MaxDB PHP client constants

ConstantDescription
MAXDB_COMPNAMEThe component name used to initialise the SQLDBC runtime environment.
MAXDB_APPLICATIONThe application to be connected to the database.
MAXDB_APPVERSIONThe version of the application.
MAXDB_SQLMODEThe SQL mode.
MAXDB_UNICODETRUE, if the connection is an unicode (UCS2) client or FALSE, if not.
MAXDB_TIMEOUT The maximum allowed time of inactivity after which the connection to the database is closed by the system.
MAXDB_ISOLATIONLEVEL Specifies whether and how shared locks and exclusive locks are implicitly requested or released.
MAXDB_PACKETCOUNT The number of different request packets used for the connection.
MAXDB_STATEMENTCACHESIZE The number of prepared statements to be cached for the connection for re-use.
MAXDB_CURSORPREFIX The prefix to use for result tables that are automatically named.

The function maxdb_fetch_array() uses a constant for the different types of result arrays. The following constants are defined:

Table 3. MaxDB fetch constants

ConstantDescription
MAXDB_ASSOC Columns are returned into the array having the fieldname as the array index.
MAXDB_ASSOC_UPPER Columns are returned into the array having the upper case fieldname as the array index.
MAXDB_ASSOC_LOWER Columns are returned into the array having the lower case fieldname as the array index.
MAXDB_BOTH Columns are returned into the array having both a numerical index and the fieldname as the array index.
MAXDB_NUM Columns are returned into the array having a numerical index to the fields. This index starts with 0, the first field in the result.

Examples

All examples in the MaxDB PHP documentation use the HOTELDB demo database from MaxDB. More about this database can be found at http://dev.mysql.com/doc/maxdb/en/98/11b83fa6b33c17e10000000a114084/frameset.htm.

To use the examples in the MaxDB PHP documentation, you have to load the tutorial data into your database. Then you have to set maxdb.default_db in php.ini to the database that contains the tutorial data.

This simple example shows how to connect, execute a query, print resulting rows and disconnect from a MaxDB database.

Example 1. MaxDB extension overview example

<?php
$link
= maxdb_connect("localhost", "MONA", "RED", "DEMODB");
   
/* check connection */
if (maxdb_connect_errno()) {
   
printf("Connect failed: %s\n", maxdb_connect_error());
   exit();
}

/* Performing SQL query */
$query = "SELECT * FROM hotel.city";
$result = maxdb_query($link, $query) or die("Query failed : " . maxdb_error());

/* Printing results in HTML */
echo "<table>\n";
while (
$line = maxdb_fetch_array($result, MAXDB_ASSOC)) {
    echo
"  <tr>\n";
    foreach (
$line as $col_value) {
        echo
"    <td>$col_value</td>\n";
    }
    echo
"  </tr>\n";
}
echo
"</table>\n";

/* Free resultset */
maxdb_free_result($result);

/* Closing connection */
maxdb_close($link);
?>

The following example shows how to bind variables to a SELECT INTO statement.

Example 2. Example for use of SELECT INTO statements

<?php
$link
= maxdb_connect("localhost", "MONA", "RED", "DEMODB");

/* check connection */
if (!$link) {
   
printf("Connect failed: %s\n", maxdb_connect_error());
   exit();
}
   
/* Performing SQL query */
$stmt = maxdb_prepare ($link, "SELECT percentage INTO ? FROM hotel.countrylanguage where language = ?");
if (!
$stmt) {
  
printf ("Prepare failed: %s\n", maxdb_error($link));
}

$name = "Mbundu";

maxdb_stmt_bind_param($stmt, 'ds', $percentage, $name);
maxdb_stmt_execute($stmt);

printf ("%f\n", $percentage);

maxdb_stmt_close ($stmt);
?>

The following example shows how to use MaxDB database procedures.

Example 3. Example fore using database procedures

<?php
$link
= maxdb_connect("localhost", "MONA", "RED", "DEMODB");

/* check connection */
if (!$link) {
   
printf("Connect failed: %s\n", maxdb_connect_error());
   exit();
}

maxdb_report (MAXDB_REPORT_OFF);
maxdb_query($link,"DROP DBPROC test_proc");
maxdb_report (MAXDB_REPORT_ERROR);

$query = "create dbproc test_proc (INOUT e_text char(72)) AS select * from SYSDBA.DUAL; fetch into :e_text;";

maxdb_query($link, $query);

/* Performing SQL query */
$stmt = maxdb_prepare ($link, "CALL test_proc (?)");
if (!
$stmt) {
  
printf ("Prepare failed: %s\n", maxdb_error($link));
}

maxdb_stmt_bind_param($stmt, 's', $result);
maxdb_stmt_execute($stmt);

printf ("%s\n", $result);

maxdb_stmt_close ($stmt);
?>

Table of Contents
maxdb_affected_rows -- Gets the number of affected rows in a previous MaxDB operation
maxdb_autocommit -- Turns on or off auto-commiting database modifications
maxdb_bind_param -- Alias of maxdb_stmt_bind_param()
maxdb_bind_result -- Alias of maxdb_stmt_bind_result()
maxdb_change_user -- Changes the user of the specified database connection
maxdb_character_set_name -- Returns the default character set for the database connection
maxdb_client_encoding -- Alias of maxdb_character_set_name()
maxdb_close_long_data -- Alias of maxdb_stmt_close_long_data()
maxdb_close -- Closes a previously opened database connection
maxdb_commit -- Commits the current transaction
maxdb_connect_errno -- Returns the error code from last connect call
maxdb_connect_error -- Returns a string description of the last connect error
maxdb_connect -- Open a new connection to the MaxDB server
maxdb_data_seek -- Adjusts the result pointer to an arbitary row in the result
maxdb_debug -- Performs debugging operations
maxdb_disable_reads_from_master -- Disable reads from master
maxdb_disable_rpl_parse -- Disable RPL parse
maxdb_dump_debug_info -- Dump debugging information into the log
maxdb_embedded_connect -- Open a connection to an embedded MaxDB server
maxdb_enable_reads_from_master -- Enable reads from master
maxdb_enable_rpl_parse -- Enable RPL parse
maxdb_errno -- Returns the error code for the most recent function call
maxdb_error -- Returns a string description of the last error
maxdb_escape_string -- Alias of maxdb_real_escape_string()
maxdb_execute -- Alias of maxdb_stmt_execute()
maxdb_fetch_array -- Fetch a result row as an associative, a numeric array, or both
maxdb_fetch_assoc -- Fetch a result row as an associative array
maxdb_fetch_field_direct --  Fetch meta-data for a single field
maxdb_fetch_field -- Returns the next field in the result set
maxdb_fetch_fields -- Returns an array of resources representing the fields in a result set
maxdb_fetch_lengths -- Returns the lengths of the columns of the current row in the result set
maxdb_fetch_object -- Returns the current row of a result set as an object
maxdb_fetch_row -- Get a result row as an enumerated array
maxdb_fetch -- Alias of maxdb_stmt_fetch()
maxdb_field_count -- Returns the number of columns for the most recent query
maxdb_field_seek --  Set result pointer to a specified field offset
maxdb_field_tell --  Get current field offset of a result pointer
maxdb_free_result -- Frees the memory associated with a result
maxdb_get_client_info -- Returns the MaxDB client version as a string
maxdb_get_client_version -- Get MaxDB client info
maxdb_get_host_info -- Returns a string representing the type of connection used
maxdb_get_metadata -- Alias of maxdb_stmt_result_metadata()
maxdb_get_proto_info -- Returns the version of the MaxDB protocol used
maxdb_get_server_info -- Returns the version of the MaxDB server
maxdb_get_server_version -- Returns the version of the MaxDB server as an integer
maxdb_info -- Retrieves information about the most recently executed query
maxdb_init --  Initializes MaxDB and returns an resource for use with maxdb_real_connect
maxdb_insert_id -- Returns the auto generated id used in the last query
maxdb_kill -- Disconnects from a MaxDB server
maxdb_master_query -- Enforce execution of a query on the master in a master/slave setup
maxdb_more_results -- Check if there any more query results from a multi query
maxdb_multi_query -- Performs a query on the database
maxdb_next_result -- Prepare next result from multi_query
maxdb_num_fields --  Get the number of fields in a result
maxdb_num_rows --  Gets the number of rows in a result
maxdb_options -- Set options
maxdb_param_count -- Alias of maxdb_stmt_param_count()
maxdb_ping --  Pings a server connection, or tries to reconnect if the connection has gone down
maxdb_prepare --  Prepare a SQL statement for execution
maxdb_query -- Performs a query on the database
maxdb_real_connect -- Opens a connection to a MaxDB server
maxdb_real_escape_string --  Escapes special characters in a string for use in a SQL statement, taking into account the current charset of the connection
maxdb_real_query -- Execute an SQL query
maxdb_report -- Enables or disables internal report functions
maxdb_rollback -- Rolls back current transaction
maxdb_rpl_parse_enabled -- Check if RPL parse is enabled
maxdb_rpl_probe -- RPL probe
maxdb_rpl_query_type -- Returns RPL query type
maxdb_select_db -- Selects the default database for database queries
maxdb_send_long_data -- Alias of maxdb_stmt_send_long_data()
maxdb_send_query -- Send the query and return
maxdb_server_end -- Shut down the embedded server
maxdb_server_init -- Initialize embedded server
maxdb_set_opt -- Alias of maxdb_options()
maxdb_sqlstate -- Returns the SQLSTATE error from previous MaxDB operation
maxdb_ssl_set -- Used for establishing secure connections using SSL
maxdb_stat -- Gets the current system status
maxdb_stmt_affected_rows -- Returns the total number of rows changed, deleted, or inserted by the last executed statement
maxdb_stmt_bind_param -- Binds variables to a prepared statement as parameters
maxdb_stmt_bind_result -- Binds variables to a prepared statement for result storage
maxdb_stmt_close_long_data -- Ends a sequence of maxdb_stmt_send_long_data()
maxdb_stmt_close -- Closes a prepared statement
maxdb_stmt_data_seek -- Seeks to an arbitray row in statement result set
maxdb_stmt_errno -- Returns the error code for the most recent statement call
maxdb_stmt_error -- Returns a string description for last statement error
maxdb_stmt_execute -- Executes a prepared Query
maxdb_stmt_fetch --  Fetch results from a prepared statement into the bound variables
maxdb_stmt_free_result -- Frees stored result memory for the given statement handle
maxdb_stmt_init --  Initializes a statement and returns an resource for use with maxdb_stmt_prepare
maxdb_stmt_num_rows -- Return the number of rows in statements result set
maxdb_stmt_param_count -- Returns the number of parameter for the given statement
maxdb_stmt_prepare --  Prepare a SQL statement for execution
maxdb_stmt_reset -- Resets a prepared statement
maxdb_stmt_result_metadata -- Returns result set metadata from a prepared statement
maxdb_stmt_send_long_data -- Send data in blocks
maxdb_stmt_sqlstate -- Returns SQLSTATE error from previous statement operation
maxdb_stmt_store_result -- Transfers a result set from a prepared statement
maxdb_store_result -- Transfers a result set from the last query
maxdb_thread_id -- Returns the thread ID for the current connection
maxdb_thread_safe -- Returns whether thread safety is given or not
maxdb_use_result -- Initiate a result set retrieval
maxdb_warning_count -- Returns the number of warnings from the last query for the given link