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

public PDOStatement PDO::query ( string $statement )

public PDOStatement PDO::query ( string $statement , int $PDO::FETCH_COLUMN , int $colno )

public PDOStatement PDO::query ( string $statement , int $PDO::FETCH_CLASS , string $classname , array $ctorargs )

public PDOStatement PDO::query ( string $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);