PDO::query
(PHP 5 >= 5.1.0, PECL pdo >= 0.2.0)
PDO::query — Executes an SQL statement, returning a result set as a PDOStatement object
说明
$statement
)$statement
, int $PDO::FETCH_COLUMN
, int $colno
)$statement
, int $PDO::FETCH_CLASS
, string $classname
, array $ctorargs
)$statement
, int $PDO::FETCH_INTO
, object $object
)PDO::query() executes an SQL statement in a single function call, returning the result set (if any) returned by the statement as a PDOStatement object.
For a query that you need to issue multiple times, you will realize better performance if you prepare a PDOStatement object using PDO::prepare() and issue the statement with multiple calls to PDOStatement::execute() .
If you do not fetch all of the data in a result set before issuing your next call to PDO::query() , your call may fail. Call PDOStatement::closeCursor() to release the database resources associated with the PDOStatement object before issuing your next call to PDO::query() .
Note:
Although this function is only documented as having a single parameter, you may pass additional arguments to this function. They will be treated as though you called PDOStatement::setFetchMode() on the resultant statement object.
参数
-
statement -
The SQL statement to prepare and execute.
Data inside the query should be properly escaped.
返回值
PDO::query() returns a PDOStatement object, or FALSE
on failure.
范例
Example #1 Demonstrate PDO::query
A nice feature of PDO::query() is that it enables you to iterate over the rowset returned by a successfully executed SELECT statement.
<?php
function getFruit ( $conn ) {
$sql = 'SELECT name, color, calories FROM fruit ORDER BY name' ;
foreach ( $conn -> query ( $sql ) as $row ) {
print $row [ 'name' ] . "\t" ;
print $row [ 'color' ] . "\t" ;
print $row [ 'calories' ] . "\n" ;
}
}
?> 以上例程会输出：
apple red 150 banana yellow 250 kiwi brown 75 lemon yellow 25 orange orange 300 pear green 150 watermelon pink 90
参见
- PDO::exec() - 执行一条 SQL 语句，并返回受影响的行数
- PDO::prepare() - Prepares a statement for execution and returns a statement object
- PDOStatement::execute() - 执行一条预处理语句
用户评论:
[#1] tgrl5000 [2015-05-21 15:42:16]
Connecting
==============================
<?php
try{
$db = new PDO("dbtype:host=yourhost;dbname=yourdbname;charset=utf8","username","password");
}catch(PDOException $e ){
echo "Error: ".$e;
}
?>
Excute query with secure data
==============================
<?php
try{
$db = new PDO("dbtype:host=yourhost;dbname=yourdbname;charset=utf8","username","password");
$mysecuredata=14;
$db->query("Select * from table where id=".$mysecuredata);
}catch(PDOException $e ){
echo "Error: ".$e;
}
?>
Excute query with insecure data
==============================
<?php
try{
$db = new PDO("dbtype:host=yourhost;dbname=yourdbname;charset=utf8","username","password");
$myinsecuredata=$_GET["id"];
$query=$db->prepare("Select * from table where id=?");
$query->excute(array($myinsecuredata));
}catch(PDOException $e ){
echo "Error: ".$e;
}
?>
Getting Data in database
==============================
<?php
try{
$db = new PDO("dbtype:host=yourhost;dbname=yourdbname;charset=utf8","username","password");
$myinsecuredata=$_GET["table"];
$query=$db->prepare("Select * from ?");
$query->excute(array($myinsecuredata));
while($row=$query->fetch(PDO::FETCH_OBJ)) {
echo $row->yourcolumnname;
}
}catch(PDOException $e ){
echo "Error: ".$e;
}
?>
Reference
==============================
http://gencbilgin.net/pdo-kullanimi-php-de-veritabani-islemleri.html
[#2] stefano[dot]bertoli [at] gmail[dot]com [2014-09-08 14:14:51]
Trying to pass like second argument PDO::FETCH_ASSOC it still work.
So passing FETCH TYPE like argument seems work.
This save you from something like:
<?php
$result = $stmt->setFetchMode(PDO::FETCH_NUM);
?>
Example:
<?php
$res = $db->query('SELECT * FROM `mytable` WHERE true', PDO::FETCH_ASSOC);
?>
[#3] paolo at dellunto dot net [2013-10-13 23:21:08]
If you are using PDO to create an SQLite dbfile that will be used by an Android application, you can set common values via the $dbh->query("PRAGMA ...") statement;
a tipical example would be the user_version of the database or the page_size
<?php
...
$dbh = new PDO($PDO_DSN, null, null, null);
$dbh->query("PRAGMA page_size = 4096"); //Android match page size
$dbh->query("PRAGMA user_version = 2"); //This match super(context, DB_NAME, null, DB_VERSION) of the DatabaseOpenHelper
....
?>
[#4] marcos at marcosregis dot com [2008-09-24 09:14:18]
After a lot of hours working with DataLink on Oracle->MySQL and PDO we (me and Adriano Rodrigues, that solve it) discover that PDO (and oci too) need the attribute AUTOCOMMIT set to FALSE to work correctly with.
There's 3 ways to set autocommit to false: On constructor, setting the atribute after construct and before query data or initiating a Transaction (that turns off autocommit mode)
The examples:
<?php
// First way - On PDO Constructor
$options = array(PDO::ATTR_AUTOCOMMIT=>FALSE);
$pdo = new PDO($dsn,$user,$pass,$options);
// now we are ready to query DataLinks
?>
<?php
// Second Way - Before create statements
$pdo = new PDO($dsn,$user,$pass);
$pdo->setAttribute(PDO::ATTR_AUTOCOMMIT,FALSE);
// or
$pdo->beginTransaction();
// now we are ready to query DataLinks
?>
To use DataLinks on oci just use OCI_DEFAULT on oci_execute() function;
[#5] andrea at bhweb dot it [2008-07-16 03:57:23]
If someone is suffering of the "MySQL server has gone away" problem after executing multiple queries, this is a solution that solved it for me. It's similar to the one needed for the exact same problem in mysqli.
<?php
$stmt=$db->prepare($query);
$stmt->execute();
do { $stmt->fetch(); $stmt->closeCursor(); ++$line; } while($stmt-
>nextRowset());
?>
I found this only works using prepare and execute this way, not if you
directly execute the query with query().
[#6] NUNTIUS [2008-01-22 09:01:11]
I found this method extremely useful for getting the iteration count. Note the usage of "for" instead of "while" or "foreach". Just place the "$row = $query->fetch()" as the second condition of your for loop (which is do until). This is the best of both worlds IMHO. Criticism welcome.
try {
$hostname = "servername";
$dbname = "dbname";
$username = "username";
$pw = "password";
$pdo = new PDO ("mssql:host=$hostname;dbname=$dbname","$username","$pw");
} catch (PDOException $e) {
echo "Failed to get DB handle: " . $e->getMessage() . "\n";
exit;
}
$query = $pdo->prepare("select name FROM tbl_name");
$query->execute();
for($i=0; $row = $query->fetch(); $i++){
echo $i." - ".$row['name']."<br/>";
}
unset($pdo);
unset($query);
[#7] fredrik at NOSPAM dot rambris dot com [2007-05-05 09:04:15]
The handling of errors by this function is controlled by the attribute PDO::ATTR_ERRMODE.
Use the following to make it throw an exception:
<?php
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
?>
[#8] nicobn at gmail dot com [2007-04-26 15:29:48]
Please note that when Query() fails, it does not return a PDOStatement object . It simply returns false.
[#9] jonmsawyer at gmail dot com [2007-01-23 12:03:41]
@ dozoyousan at gmail dot com
> 03-May-2006 05:26
> > When query() fails, the boolean false is returned.
>
> I think that is "Silent Mode".
> If that set attribute ErrorMode "Exception Mode"
> then that throw PDOException.
> $pdoObj = new PDO( $dsn, $user, $pass );
> $pdoObj->setAttribute("PDO::ATTR_ERRMODE",
> PDO::ERRMODE_EXCEPTION);
What you say is correct, however, your PHP code is incorrect:
<?php
// This is fine
$pdoObj = new PDO( $dsn, $user, $pass );
// This line is wrong
$pdoObj->setAttribute("PDO::ATTR_ERRMODE", PDO::ERRMODE_EXCEPTION);
// It should be:
$pdoObj->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
// Parameter 1 should not be in quotes. PHP interprets
// that as a string. Instead, internally, its represented
// as type LONG INT. Try it :)
?>
Hope this helps. Cheers.
[#10] dozoyousan at gmail dot com [2006-05-02 22:26:29]
> When query() fails, the boolean false is returned.
I think that is "Silent Mode".
If that set attribute ErrorMode "Exception Mode"
then that throw PDOException.
$pdoObj = new PDO( $dsn, $user, $pass );
$pdoObj->setAttribute("PDO::ATTR_ERRMODE", PDO::ERRMODE_EXCEPTION);