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MySQLi 扩展库

简介

mysqli 扩展允许用户访问由 MySQL 4.1 或更高版本所提供的功能。有关 MySQL 数据库服务器的更多信息见 » https://www.mysql.com/

MySQL 的文档见 » https://dev.mysql.com/doc/

经 MySQL AB 授权,本文档中包括部分 MySQL 手册的内容。

需求

要使用本扩展库中的函数,必须在编译 PHP 时加入 mysqli 扩展的支持。

Note: mysqli 扩展库是设计用于同 MySQL 4.1.3 或更高版本协同工作的。对之前版本,请参考 MySQL 扩展库文档。

安装

要安装 PHP 的 mysqli 扩展,配置时加上 --with-mysqli=mysql_config_path/mysql_config。其中 mysql_config_path 表示 mysql_config 程序的路径,该程序随 MySQL 大于 4.1 版本一起发布。

如果要同时安装 mysql 和 mysqli 扩展,必须使用同一个客户端库以避免冲突。

运行时配置

这些函数的行为受 php.ini 的影响。

MySQLi 配置选项
名称 默认值 可修改范围 更新日志
mysqli.max_links "-1" PHP_INI_SYSTEM 自 PHP 5.0.0 起可用。
mysqli.default_port "3306" PHP_INI_ALL 自 PHP 5.0.0 起可用。
mysqli.default_socket NULL PHP_INI_ALL 自 PHP 5.0.0 起可用。
mysqli.default_host NULL PHP_INI_ALL 自 PHP 5.0.0 起可用。
mysqli.default_user NULL PHP_INI_ALL 自 PHP 5.0.0 起可用。
mysqli.default_pw NULL PHP_INI_ALL 自 PHP 5.0.0 起可用。

以上 PHP_INI_* 常量的进一步细节及定义,见怎样修改配置设定一节。

以下是配置选项的简要解释。

每个进程的 MySQL 连接的最大数目。

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_pw string

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

预定义类

mysqli

表达了 PHP 和 MySQL 数据库之间的连接。

构造函数

  • mysqli - 构造一个新的 mysqli 对象

方法

  • autocommit - 打开或关闭自动提交的数据库选项

  • change_user - 改变指定的数据库连接的用户

  • character_set_name - 返回数据库连接的默认字符集

  • close - 关闭一个之前打开的连接

  • commit - 提交当前事务

  • connect - 打开一个到 MySQL 数据库服务器的新连接

  • debug - 执行排错操作

  • dump_debug_info - 取得排错信息

  • get_client_info - 返回客户端版本

  • get_host_info - 返回连接使用的类型

  • get_server_info - 返回 MySQL 服务器的版本

  • get_server_version - 返回 MySQL 服务器的版本

  • init - 初始化 mysqli 对象

  • info - 取得最近执行的查询的信息

  • kill - 要求服务器停止一个 mysql 线程

  • multi_query - 执行多个查询

  • 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 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

  • set_charset - sets the default client character set

  • ssl_set - sets ssl parameters

  • stat - gets the current system status

  • stmt_init- initializes a statement for use with mysqli_stmt_prepare

  • store_result - transfers a resultset from last query

  • thread_safe - returns whether thread safety is given or not

  • use_result - transfers an unbuffered resultset from last query

属性

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

  • client_info - returns the MySQL client version as a string

  • client_version - returns the MySQL 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 MySQL protocol used

  • server_info - returns a string that represents the server version number

  • server_version - returns the version number of the server as an integer

  • 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

mysqli_stmt

表达了一个预备好的语句。

方法

  • 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

  • prepare - prepares a SQL query

  • reset - resets a prepared statement

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

  • send_long_data - sends data in chunks

  • store_result - buffers complete resultset from a prepared statement

属性

  • affected_rows - returns affected rows from last statement execution

  • errno - returns errorcode for last statement function

  • error - returns errormessage for last statement function

  • field_count - returns the number of columns in a result set

  • id - returns the statement identifier

  • insert_id - returns the value generated for an AUTO_INCREMENT column by the prepared statement

  • num_rows - returns the number of rows in the result set

  • 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

mysqli_result

表达了对数据库的查询所返回的结果集。

方法

属性

  • current_field - returns offset of current fieldpointer

  • field_count - returns number of fields in resultset

  • lengths - returns an array of columnlengths

  • num_rows - returns number of rows in resultset

  • type - returns MYSQLI_STORE_RESULT or MYSQLI_USE_RESULT

预定义常量

MySQLi 常量
名称 说明
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 a 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_NEWDECIMAL (integer) Precision math DECIMAL or NUMERIC field (MySQL 5.0.3 and up)
MYSQLI_TYPE_BIT (integer) Field is defined as BIT (MySQL 5.0.3 and up)
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 INT
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) Field is defined as MEDIUMINT
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_VAR_STRING (integer) Field is defined as VARCHAR
MYSQLI_TYPE_STRING (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
MYSQLI_DATA_TRUNCATED (integer) Data truncation occurred. Available since PHP 5.1.0 and MySQL 5.0.5.

例子

在 MySQLI 文档中的所有例子都使用了来自 MySQL AB 的 world 数据库。数据库 world 可以在此地址下载:» https://dev.mysql.com/get/Downloads/Manual/world.sql.gz/from/pick

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