LXV. Improved MySQL Extension

Introduction

The mysqli extension allows you to access the functionality provided by MySQL 4.1 and above. More information about the MySQL Database server can be found at http://www.mysql.com/

Documentation for MySQL can be found at http://www.mysql.com/documentation/.

Parts of this documentation included from MySQL manual with permissions of MySQL AB.

Requirements

In order to have these functions available, you must compile PHP with support for the mysqli extension.

Note: The mysqli extension is designed to work with the version 4.1.2 or above of MySQL. For previous versions, please see the MySQL extension documentation.

Installation

To install the mysqli extension for PHP, use the --with-mysqli=mysql_config_path configuration option where mysql_config_path represents the location of the mysql_config program that comes with MySQL versions greater than 4.1. Also, disable the standard MySQL extension (which is enabled by default) by also using the --without-mysql configuration option. If you would like to install the standard mysql extension along with the mysqli extension, the bundled libmysql library that comes with PHP cannot be used. Instead, use the client libraries installed by MySQL with versions below 4.1. This will force PHP to use the client libraries installed by MySQL thus avoiding any conflicts.

Runtime Configuration

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

Table 1. MySQLi Configuration Options

NameDefaultChangeable
mysqli.max_links"-1"PHP_INI_SYSTEM
mysqli.default_portNULLPHP_INI_ALL
mysqli.default_socketNULLPHP_INI_ALL
mysqli.default_hostNULLPHP_INI_ALL
mysqli.default_userNULLPHP_INI_ALL
mysqli.default_pwNULLPHP_INI_ALL

For further details and definitions of the above PHP_INI_* constants, see the chapter on configuration changes.

Here's a short explanation of the configuration directives.

mysqli.max_links integer

The maximum number of MySQL connections per process, including persistent connections.

mysqli.default_port string

The default TCP port number to use when connecting to the database server if no other port is specified. If no default is specified, the port will be obtained from the MYSQL_TCP_PORT environment variable, the mysql-tcp entry in /etc/services or the compile-time MYSQL_PORT constant, in that order. Win32 will only use the MYSQL_PORT constant.

mysqli.default_socket string

The default socket name to use when connecting to a local database server if no other socket name is specified.

mysqli.default_host string

The default server host to use when connecting to the database server if no other host is specified. Doesn't apply in safe mode.

mysqli.default_user string

The default user name to use when connecting to the database server if no other name is specified. Doesn't apply in safe mode.

mysqli.default_password string

The default password to use when connecting to the database server if no other password is specified. Doesn't apply in safe mode.

Predefined Classes

mysqli

Represents a connection between PHP and a MySQL database.

Constructor

  • mysqli() - construct a new mysqli 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 MySQL 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 MySQL server

  • init - initializes mysqli object

  • info - retrieves information about the most recently executed query

  • kill - asks the server to kill a mysql thread

  • multi_query - performs multiple queries

  • more_results - check if more results exists 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 MySQL 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_initInitializes a statement for use with mysqli_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 MySQL operation

  • 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 MySQL 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

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

  • get_metadata - Retrieves a resultset from a prepared statement for metadata information

  • prepare - prepares a SQL query

  • send_long_data - Sends data in chunks

  • 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

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

Table 2. MySQLi Constants

NameDescription
MYSQLI_READ_DEFAULT_GROUP (integer) Read options from the named group from `my.cnf' or the file specified with MYSQLI_READ_DEFAULT_FILE
MYSQLI_READ_DEFAULT_FILE (integer) Read options from the named option file instead of from my.cnf
MYSQLI_OPT_CONNECT_TIMEOUT (integer) Connect timeout in seconds
MYSQLI_OPT_LOCAL_INFILE (integer) Enables command LOAD LOCAL INFILE
MYSQLI_INIT_COMMAND (integer) Command to execute when connecting to MySQL server. Will automatically be re-executed when reconnecting.
MYSQLI_CLIENT_SSL (integer) Use SSL (encrypted protocol). This option should not be set by application programs; it is set internally in the MySQL client library
MYSQLI_CLIENT_COMPRESS (integer) Use compression protocol
MYSQLI_CLIENT_INTERACTIVE (integer) Allow interactive_timeout seconds (instead of wait_timeout seconds) of inactivity before closing the connection. The client's session wait_timeout variable will be set to the value of the session interactive_timeout variable.
MYSQLI_CLIENT_IGNORE_SPACE (integer) Allow spaces after function names. Makes all functions names reserved words.
MYSQLI_CLIENT_NO_SCHEMA (integer) Don't allow the db_name.tbl_name.col_name syntax.
MYSQLI_CLIENT_MULTI_QUERIES (integer)  
MYSQLI_STORE_RESULT (integer) For using buffered resultsets
MYSQLI_USE_RESULT (integer) For using unbuffered resultsets
MYSQLI_ASSOC (integer) Columns are returned into the array having the fieldname as the array index.
MYSQLI_NUM (integer) Columns are returned into the array having an enumerated index.
MYSQLI_BOTH (integer) Columns are returned into the array having both a numerical index and the fieldname as the associative index.
MYSQLI_NOT_NULL_FLAG (integer) Indicates that a field is defined as NOT NULL
MYSQLI_PRI_KEY_FLAG (integer) Field is part of a primary index
MYSQLI_UNIQUE_KEY_FLAG (integer) Field is part of an unique index.
MYSQLI_MULTIPLE_KEY_FLAG (integer) Field is part of an index.
MYSQLI_BLOB_FLAG (integer) Field is defined as BLOB
MYSQLI_UNSIGNED_FLAG (integer) Field is defined as UNSIGNED
MYSQLI_ZEROFILL_FLAG (integer) Field is defined as ZEROFILL
MYSQLI_AUTO_INCREMENT_FLAG (integer) Field is defined as AUTO_INCREMENT
MYSQLI_TIMESTAMP_FLAG (integer) Field is defined as TIMESTAMP
MYSQLI_SET_FLAG (integer) Field is defined as SET
MYSQLI_NUM_FLAG (integer) Field is defined as NUMERIC
MYSQLI_PART_KEY_FLAG (integer) Field is part of an multi-index
MYSQLI_GROUP_FLAG (integer) Field is part of GROUP BY
MYSQLI_TYPE_DECIMAL (integer) Field is defined as DECIMAL
MYSQLI_TYPE_TINY (integer) Field is defined as TINYINT
MYSQLI_TYPE_SHORT (integer) Field is defined as INT
MYSQLI_TYPE_LONG (integer) Field is defined as MEDIUMINT
MYSQLI_TYPE_FLOAT (integer) Field is defined as FLOAT
MYSQLI_TYPE_DOUBLE (integer) Field is defined as double
MYSQLI_TYPE_NULL (integer) Field is defined as DEFAULT NULL
MYSQLI_TYPE_TIMESTAMP (integer) Field is defined as TIMESTAMP
MYSQLI_TYPE_LONGLONG (integer) Field is defined as BIGINT
MYSQLI_TYPE_INT24 (integer)  
MYSQLI_TYPE_DATE (integer) Field is defined as DATE
MYSQLI_TYPE_TIME (integer) Field is defined as TIME
MYSQLI_TYPE_DATETIME (integer) Field is defined as DATETIME
MYSQLI_TYPE_YEAR (integer) Field is defined as YEAR
MYSQLI_TYPE_NEWDATE (integer) Field is defined as DATE
MYSQLI_TYPE_ENUM (integer) Field is defined as ENUM
MYSQLI_TYPE_SET (integer) Field is defined as SET
MYSQLI_TYPE_TINY_BLOB (integer) Field is defined as TINYBLOB
MYSQLI_TYPE_MEDIUM_BLOB (integer) Field is defined as MEDIUMBLOB
MYSQLI_TYPE_LONG_BLOB (integer) Field is defined as LONGBLOB
MYSQLI_TYPE_BLOB (integer) Field is defined as BLOB
MYSQLI_TYPE_STRING (integer) Field is defined as VARCHAR
MYSQLI_TYPE_CHAR (integer) Field is defined as CHAR
MYSQLI_TYPE_GEOMETRY (integer) Field is defined as GEOMETRY
MYSQLI_NEED_DATA (integer) More data available for bind variable
MYSQLI_NO_DATA (integer) No more data available for bind variable

Examples

All Examples in the MySQLI documentation use the world database from MySQL AB. The world database can be found at http://www.mysql.com/get/Downloads/Manual/world.sql.gz/from/pick

Table of Contents
mysqli_affected_rows -- Gets the number of affected rows in a previous MySQL operation
mysqli_autocommit -- Turns on or off auto-commiting database modifications
mysqli_bind_param -- Alias for mysqli_stmt_bind_param()
mysqli_bind_result -- Alias for mysqli_stmt_bind_result()
mysqli_change_user -- Changes the user of the specified database connection
mysqli_character_set_name -- Returns the default character set for the database connection
mysqli_client_encoding -- Alias of mysqli_character_set_name()
mysqli_close -- Closes a previously opened database connection
mysqli_commit -- Commits the current transaction
mysqli_connect_errno -- Returns the error code from last connect call
mysqli_connect_error -- Returns a string description of the last connect error
mysqli_connect -- Open a new connection to the MySQL server
mysqli_data_seek -- Adjusts the result pointer to an arbitary row in the result
mysqli_debug -- Performs debugging operations
mysqli_disable_reads_from_master -- 
mysqli_disable_rpl_parse -- 
mysqli_dump_debug_info -- Dump debugging information into the log
mysqli_embedded_connect -- Open a connection to an embedded mysql server.
mysqli_enable_reads_from_master -- 
mysqli_enable_rpl_parse -- 
mysqli_errno -- Returns the error code for the most recent function call
mysqli_error -- Returns a string description of the last error
mysqli-escape-string -- Alias of mysqli_real_escape_string()
mysqli_execute -- Alias for mysqli_stmt_execute()
mysqli_fetch_array -- Fetch a result row as an associative, a numeric array, or both.
mysqli_fetch_assoc -- Fetch a result row as an associative array
mysqli_fetch_field_direct --  Fetch meta-data for a single field
mysqli_fetch_field -- Returns the next field in the result set
mysqli_fetch_fields -- Returns an array of objects representing the fields in a result set
mysqli_fetch_lengths -- Returns the lengths of the columns of the current row in the result set
mysqli_fetch_object -- Returns the current row of a result set as an object
mysqli_fetch_row -- Get a result row as an enumerated array
mysqli_fetch -- Alias for mysqli_stmt_fetch()
mysqli_field_count -- Returns the number of columns for the most recent query
mysqli_field_seek --  Set result pointer to a specified field offset
mysqli_field_tell --  Get current field offset of a result pointer
mysqli_free_result -- Frees the memory associated with a result
mysqli_get_client_info -- Returns the MySQL client version as a string
mysqli_get_client_version -- Get MySQL client info.
mysqli_get_host_info -- Returns a string representing the type of connection used
mysqli_get_metadata -- Alias for mysqli_stmt_result_metadata()
mysqli_get_proto_info -- Returns the version of the MySQL protocol used
mysqli_get_server_info -- Returns the version of the MySQL server
mysqli_get_server_version -- Returns the version of the MySQL server as an integer
mysqli_info -- Retrieves information about the most recently executed query
mysqli_init --  Initializes MySQLi and returns an object for use with mysqli_real_connect
mysqli_insert_id -- Returns the auto generated id used in the last query
mysqli_kill -- Asks the server to kill a MySQL thread
mysqli_master_query -- Enforce execution of a query on the master in a master/slave setup.
mysqli_more_results -- Check if there any more query results from a multi query.
mysqli_multi_query -- Performs a query on the database
mysqli_next_result -- prepare next result from multi_query.
mysqli_num_fields --  Get the number of fields in a result
mysqli_num_rows --  Gets the number of rows in a result
mysqli_options -- set options
mysqli_param_count -- Alias for mysqli_stmt_param_count()
mysqli_ping --  Pings a server connection, or tries to reconnect if the connection has gone down.
mysqli_prepare --  Prepare a SQL statement for execution
mysqli_query -- Performs a query on the database
mysqli_real_connect -- Opens a connection to a mysql server
mysqli_real_escape_string --  Escapes special characters in a string for use in a SQL statement, taking into account the current charset of the connection
mysqli_real_query -- Execute an SQL query
mysqli_report -- enables or disables internal report functions
mysqli_rollback -- Rolls back current transaction
mysqli_rpl_parse_enabled -- 
mysqli_rpl_probe -- 
mysqli_rpl_query_type -- 
mysqli_select_db -- Selects the default database for database queries
mysqli_send_long_data -- Alias for mysqli_stmt_send_long_data()
mysqli_send_query -- 
mysqli_server_end -- 
mysqli_server_init -- Initialize embedded server.
mysqli_set_opt -- Alias of mysqli_options()
mysqli_sqlstate -- Returns the SQLSTATE error from previous MySQL operation.
mysqli_ssl_set -- Used for establishing secure connections using SSL.
mysqli_stat -- Gets the current system status
mysqli_stmt_affected_rows -- Returns the total number of rows changed, deleted, or inserted by the last executed statement
mysqli_stmt_bind_param -- Binds variables to a prepared statement as parameters
mysqli_stmt_bind_result -- Binds variables to a prepared statement for result storage
mysqli_stmt_close -- Closes a prepared statement
mysqli_stmt_data_seek -- Seeks to an arbitray row in statement result set
mysqli_stmt_errno -- Returns the error code for the most recent statement call
mysqli_stmt_error -- Returns a string description for last statement error
mysqli_stmt_execute -- Executes a prepared Query
mysqli_stmt_fetch --  Fetch results from a prepared statement into the bound variables
mysqli_stmt-init --  Initializes a statement and returns an object for use with mysqli_stmt_prepare
mysqli_stmt_num_rows -- Return the number of rows in statements result set.
mysqli_stmt_param_count -- Returns the number of parameter for the given statement
mysqli_stmt_prepare --  Prepare a SQL statement for execution
mysqli_stmt_result_metadata -- returns result set metadata from a prepared statement
mysqli_stmt_send_long_data -- Send data in blocks
mysqli_stmt_sqlstate -- returns SQLSTATE error from previous statement operation
mysqli_stmt_store_result -- Transfers a result set from a prepared statement
mysqli_store_result -- Transfers a result set from the last query
mysqli_thread_id -- Returns the thread ID for the current connection
mysqli_thread_safe -- Returns whether thread safety is given or not
mysqli_use_result -- Initiate a result set retrieval
mysqli_warning_count -- Returns the number of warnings from the last query for the given link