mysqli::options()

(PHP 5, PHP 7)

设置选项

说明

面向对象风格
mysqli::options(int $option, mixed $value): bool

过程化风格
mysqli_options(mysqli$link,int $option, mixed $value): bool

设置一个连接的扩展选项，这些选项可以改变这个连接的行为。

如果要对多个选项进行设置，可以多次调用此函数来。

mysqli_options()需要在mysqli_init()函数之后、mysqli_real_connect()函数之前被调用。

参数

$link

仅以过程化样式：由mysqli_connect()或mysqli_init()返回的链接标识。

$option

要进行设置的选项，可以是下列中的某一项：

有效的选项

名称	描述
MYSQLI_OPT_CONNECT_TIMEOUT	连接超时设置，以秒为单位（在 Windows 平台上，PHP 5.3.1 之后才支持此选项）。
MYSQLI_OPT_LOCAL_INFILE	启用或禁用LOAD LOCAL INFILE语句
MYSQLI_INIT_COMMAND	成功建立 MySQL 连接之后要执行的 SQL 语句
MYSQLI_READ_DEFAULT_FILE	从指定的文件中读取选项，而不是使用my.cnf中的选项
MYSQLI_READ_DEFAULT_GROUP	从my.cnf或者MYSQL_READ_DEFAULT_FILE指定的文件中读取指定的组中的选项。
MYSQLI_SERVER_PUBLIC_KEY	SHA-256 认证模式下，要使用的 RSA 公钥文件。
MYSQLI_OPT_NET_CMD_BUFFER_SIZE	内部命令/网络缓冲大小，仅在 mysqlnd 驱动下有效。
MYSQLI_OPT_NET_READ_BUFFER_SIZE	以字节为单位，读取 MySQL 命令报文时候的块大小，仅在 mysqlnd 驱动下有效。
MYSQLI_OPT_INT_AND_FLOAT_NATIVE	将整数和浮点数类型的列转换成 PHP 的数值类型，仅在 mysqlnd 驱动下有效。
MYSQLI_OPT_SSL_VERIFY_SERVER_CERT

$value

选项值。

返回值

成功时返回TRUE，或者在失败时返回FALSE。

更新日志

范例

参见mysqli_real_connect()。

注释

Note:

MySQLnd 总是使用服务器的默认字符集。此字符集在连接握手／认证时发送，并被 mysqlnd使用。

Libmysqlclient 使用my.cnf中的默认字符集或者由在调用mysqli_init()之后，mysqli_real_connect()之前先调用mysqli_options()来指定。

参见

• mysqli_init() 初始化 MySQLi 并返回一个资源类型的值，这个值可以作为 mysqli_real_connect()函数的传入参数
• mysqli_real_connect() 建立一个 MySQL 服务器连接

There is an undocumented option: MYSQLI_OPT_READ_TIMEOUT. This is similar to MYSQLI_OPT_CONNECT_TIMEOUT in theory, but has a slightly different application. Connection timeout only specifies the wait time for the initial TCP connection. Once that is created, the timeout no longer applies. Read timeout, however, is from the time the TCP connection is created until the first packet of actual data is received. There are instances where a TCP connection can be established, but the MySQL server stalls indefinitely, preventing execution from ever returning to PHP. Specifying a read timeout alleviates this condition, whereas connect timeout wouldn't. 
If the MYSQLI_OPT_READ_TIMEOUT constant isn't defined, it is still supported on versions where that isn't the case. You can define it yourself in older PHP versions with the following code.
<?php
if (!defined('MYSQLI_OPT_READ_TIMEOUT')) {
  define ('MYSQLI_OPT_READ_TIMEOUT', 11);
}
?>
You can then use read timeout the same way you could a connect timeout as follows. Please note that since these are two different timeout values for two different parts of the entire connection process, the timeouts do stack (eg: 10 seconds connect timeout + 10 seconds read timeout = maximum possible timeout of 20 seconds)
<?php
//create the object
$connection = mysqli_init();
//specify the connection timeout
$connection->options(MYSQLI_OPT_CONNECT_TIMEOUT, 10);
//specify the read timeout
$connection->options(MYSQLI_OPT_READ_TIMEOUT, 10);
//initiate the connection to the server, using both previously specified timeouts
$connection->real_connect('server', 'user', 'pass', 'database');
?>

Here es little example to create a SSL Connection
<?php
$db = mysqli_init();
/*
When you want so use a separate cnf
$test = $db->options(MYSQLI_EAD_DEFAULT_FILE,'myother.cnf');
*/
$db->ssl_set('server-key.pem','server-cert.pem',
'cacert.pem',NULL,NULL);
$db->real_connect('localhost','root','','mydb');
//Here some query
$db->close();
?>

Example on using mysqli_options to increase size of max_allowed_packet for working with big blobs.
function dbConnect()
{
  $user = 'jomama';
  $pass = 'cartoon';
  $dbName = 'LifeCycle';
  $host = 'localhost';
  $mysqli = mysqli_init();
  mysqli_options($mysqli,MYSQLI_READ_DEFAULT_GROUP,
                  "max_allowed_packet=50M");
  mysqli_real_connect($mysqli,$host, $user, $pass,$dbName) 
         or die ('<P>Unable to connect</P>');
  return $mysqli;
}