On PHP 7.4.4 an unsuccessful call returns FALSE, not NULL.
(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.2.0)
PDO::getAttribute — 取回一个数据库连接的属性
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。
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_AUTOCOMMITPDO::ATTR_CASEPDO::ATTR_CLIENT_VERSIONPDO::ATTR_CONNECTION_STATUSPDO::ATTR_DRIVER_NAMEPDO::ATTR_ERRMODEPDO::ATTR_ORACLE_NULLSPDO::ATTR_PERSISTENTPDO::ATTR_PREFETCHPDO::ATTR_SERVER_INFOPDO::ATTR_SERVER_VERSIONPDO::ATTR_TIMEOUT
成功调用则返回请求的 PDO 属性值。不成功则返回 null。
Example #1 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";
}
?>
On PHP 7.4.4 an unsuccessful call returns FALSE, not NULL.
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"
As of 30-Jan-2016, MariaDB on version "5.5.5-10.1.9-MariaDB" apparently does not support: "PREFETCH" nor "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.
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 ...