PDO::getAttribute()

(PHP 5 >= 5.1.0, PHP 7, PECL pdo >= 0.2.0)

取回一个数据库连接的属性

说明

PDO::getAttribute(int $attribute): mixed

此函数（方法）返回一个数据库连接的属性值。取回 PDOStatement 属性，请参阅PDOStatement::getAttribute()。

注意有些数据库/驱动可能不支持所有的数据库连接属性。

参数

$attribute

PDO::ATTR_*常量中的一个。下列为应用到数据库连接中的常量：

• PDO::ATTR_AUTOCOMMIT
• PDO::ATTR_CASE
• PDO::ATTR_CLIENT_VERSION
• PDO::ATTR_CONNECTION_STATUS
• PDO::ATTR_DRIVER_NAME
• PDO::ATTR_ERRMODE
• PDO::ATTR_ORACLE_NULLS
• PDO::ATTR_PERSISTENT
• PDO::ATTR_PREFETCH
• PDO::ATTR_SERVER_INFO
• PDO::ATTR_SERVER_VERSION
• PDO::ATTR_TIMEOUT

返回值

成功调用则返回请求的 PDO 属性值。不成功则返回null。

范例

取回数据库连接属性

<?php
$conn = new PDO('odbc:sample', 'db2inst1', 'ibmdb2');
$attributes = array(
    "AUTOCOMMIT", "ERRMODE", "CASE", "CLIENT_VERSION", "CONNECTION_STATUS",
    "ORACLE_NULLS", "PERSISTENT", "PREFETCH", "SERVER_INFO", "SERVER_VERSION",
    "TIMEOUT"
);
foreach ($attributes as $val) {
    echo "PDO::ATTR_$val: ";
    echo $conn->getAttribute(constant("PDO::ATTR_$val")) . "\n";
}
?>

参见

• PDO::setAttribute() 设置属性
• PDOStatement::getAttribute() 检索一个语句属性
• PDOStatement::setAttribute() 设置一个语句属性

Better example that handles unsupported attributes gracefully:
<?php
$conn = new PDO( 'odbc:sample', 'db2inst1', 'ibmdb2' );
$conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
$attributes = array(
  "AUTOCOMMIT", "ERRMODE", "CASE", "CLIENT_VERSION", "CONNECTION_STATUS",
  "ORACLE_NULLS", "PERSISTENT", "PREFETCH", "SERVER_INFO", "SERVER_VERSION",
  "TIMEOUT"
);
foreach ( $attributes as $val ) {
  echo "PDO::ATTR_$val: ";
  try {
    echo $conn->getAttribute( constant( "PDO::ATTR_$val" ) ) . "\n";
  } catch ( PDOException $e ) {
    echo $e->getMessage() . "\n";
  }
}
?>

Mysql on version "5.6.29" not support "PDO::ATTR_PREFETCH" and "PDO::ATTR_TIMEOUT"

Oracle does not have the following attributes:
PDO::ATTR_CONNECTION_STATUS: SQLSTATE[IM001]: Driver does not support this function: driver does not support that attribute
PDO::ATTR_PREFETCH: SQLSTATE[IM001]: Driver does not support this function: driver does not support that attribute
PDO::ATTR_TIMEOUT: SQLSTATE[IM001]: Driver does not support this function: driver does not support that attribute
The rest work fine.

As of 30-Jan-2016, MariaDB on version "5.5.5-10.1.9-MariaDB" apparently does not support: "PREFETCH" nor "TIMEOUT".

The Oracle driver seems to not support PDO::getAttribute():
ociPHP Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[IM001]: Driver does not support this function: driver does not support getting attributes' in ...