(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.1.0)
PDO::setAttribute — Set an attribute
Sets an attribute on the database handle. Some available generic attributes are listed below; some drivers may make use of additional driver specific attributes. Note that driver specific attributes must not be used with other drivers.
PDO::ATTR_CASE Force column names to a specific case. Can take one of the following values:
PDO::CASE_LOWER PDO::CASE_NATURAL PDO::CASE_UPPER PDO::ATTR_ERRMODE Error reporting mode of PDO. Can take one of the following values:
PDO::ERRMODE_SILENT PDO::ERRMODE_WARNING E_WARNING diagnostics.
PDO::ERRMODE_EXCEPTION PDO::ATTR_ORACLE_NULLS Note: This attribute is available with all drivers, not just Oracle.
Determines if and how null and empty strings should be converted.
Can take one of the following values:
PDO::NULL_NATURAL PDO::NULL_EMPTY_STRING null .
PDO::NULL_TO_STRING null gets converted to an empty string.
PDO::ATTR_STRINGIFY_FETCHES
Controls whether fetched values (except null ) are converted to strings.
Takes a value of type bool : true to enable and false to
disable (default).
null values remain unchanged unless PDO::ATTR_ORACLE_NULLS
is set to PDO::NULL_TO_STRING .
PDO::ATTR_STATEMENT_CLASS
Set user-supplied statement class derived from PDOStatement.
Requires array(string classname, array(mixed constructor_args)).
Cannot be used with persistent PDO instances.
PDO::ATTR_TIMEOUT Specifies the timeout duration in seconds. Takes a value of type int .
Note:
Not all drivers support this option, and its meaning may differ from driver to driver. For example, SQLite will wait for up to this time value before giving up on obtaining a writable lock, but other drivers may interpret this as a connection or a read timeout interval.
PDO::ATTR_AUTOCOMMIT Note: Only available for the OCI, Firebird, and MySQL drivers.
Whether to autocommit every single statement.
Takes a value of type bool : true to enable and
false to disable. By default, true .
PDO::ATTR_EMULATE_PREPARES Note: Only available for the OCI, Firebird, and MySQL drivers.
Whether enable or disable emulation of prepared statements.
Some drivers do not support prepared statements natively or have
limited support for them.
If set to true PDO will always emulate prepared statements,
otherwise PDO will attempt to use native prepared statements.
In case the driver cannot successfully prepare the current query,
PDO will always fall back to emulating the prepared statement.
PDO::MYSQL_ATTR_USE_BUFFERED_QUERY Note: Only available for the MySQL driver.
Whether to use buffered queries.
Takes a value of type bool : true to enable and
false to disable. By default, true .
PDO::ATTR_DEFAULT_FETCH_MODE Set the default fetch mode. A description of the modes and how to use them is available in the PDOStatement::fetch() documentation.
attributeThe attribute to modify.
value
The value to set the attribute,
might require a specific type depending on the attribute.
Because no examples are provided, and to alleviate any confusion as a result, the setAttribute() method is invoked like so:
setAttribute(ATTRIBUTE, OPTION);
So, if I wanted to ensure that the column names returned from a query were returned in the case the database driver returned them (rather than having them returned in all upper case [as is the default on some of the PDO extensions]), I would do the following:
<?php
// Create a new database connection.
$dbConnection = new PDO($dsn, $user, $pass);
// Set the case in which to return column_names.
$dbConnection->setAttribute(PDO::ATTR_CASE, PDO::CASE_NATURAL);
?>
Hope this helps some of you who learn by example (as is the case with me).
.ColinThis is an update to a note I wrote earlier concerning how to set multiple attributes when you create you PDO connection string.
You can put all the attributes you want in an associative array and pass that array as the fourth parameter in your connection string. So it goes like this:
<?php
$options = [
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::ATTR_CASE => PDO::CASE_NATURAL,
PDO::ATTR_ORACLE_NULLS => PDO::NULL_EMPTY_STRING
];
// Now you create your connection string
try {
// Then pass the options as the last parameter in the connection string
$connection = new PDO("mysql:host=$host; dbname=$dbname", $user, $password, $options);
// That's how you can set multiple attributes
} catch(PDOException $e) {
die("Database connection failed: " . $e->getMessage());
}
?>Well, I have not seen it mentioned anywhere and thought its worth mentioning. It might help someone. If you are wondering whether you can set multiple attributes then the answer is yes.
You can do it like this:
try {
$connection = new PDO("mysql:host=$host; dbname=$dbname", $user, $password);
// You can begin setting all the attributes you want.
$connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$connection->setAttribute(PDO::ATTR_CASE, PDO::CASE_NATURAL);
$connection->setAttribute(PDO::ATTR_ORACLE_NULLS, PDO::NULL_EMPTY_STRING);
// That's how you can set multiple attributes
}
catch(PDOException $e)
{
die("Database connection failed: " . $e->getMessage());
}
I hope this helps somebody. :)It is worth noting that not all attributes may be settable via setAttribute(). For example, PDO::MYSQL_ATTR_MAX_BUFFER_SIZE is only settable in PDO::__construct(). You must pass PDO::MYSQL_ATTR_MAX_BUFFER_SIZE as part of the optional 4th parameter to the constructor. This is detailed in http://bugs.php.net/bug.php?id=38015 Note that contrary to most PDO methods, setAttribute does not throw a PDOException when it returns false.For PDO::ATTR_EMULATE_PREPARES, the manual states a boolean value is required. However, when getAttribute() is used to check this value, an integer (1 or 0) is returned rather than true or false.
This means that if you are checking a PDO object is configured as required then
<?php
// Check emulate prepares is off
if ($pdo->getAttribute(\PDO::ATTR_EMULATE_PREPARES) !== false) {
/* do something */
}
?>
will always 'do something', regardless.
Either
<?php
// Check emulate prepares is off
if ($pdo->getAttribute(\PDO::ATTR_EMULATE_PREPARES) != false) {
/* do something */
}
?>
or
<?php
// Check emulate prepares is off
if ($pdo->getAttribute(\PDO::ATTR_EMULATE_PREPARES) !== 0) {
/* do something */
}
?>
is needed instead.
Also worth noting that setAttribute() does, in fact, accept an integer value if you want to be consistent.There is also a way to specifie the default fetch mode :
<?php
$connection = new PDO($connection_string);
$connection->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
?>Note that in order for
\PDO::ATTR_TIMEOUT
to have any effect, you must set
\PDO::ATTR_ERRMODE=>\PDO::ERRMODE_EXCEPTION.
If
\PDO::ATTR_ERRMODE=>\PDO::ERRMODE_WARNING
it doesn't appear to do anything.