PDO::query

Άρθρο
11/18/2022

Executes a SQL query and returns a result set as a PDOStatement object.

Syntax

  
PDOStatement PDO::query ($statement[, $fetch_style);

Parameters

$statement: The SQL statement you want to execute.

$fetch_style: The optional instructions on how to perform the query. See the Remarks section for more details. $fetch_style in PDO::query can be overridden with $fetch_style in PDO::fetch.

Return Value

If the call succeeds, PDO::query returns a PDOStatement object. If the call fails, PDO::query throws a PDOException object or returns false, depending on the setting of PDO::ATTR_ERRMODE.

Exceptions

PDOException.

Remarks

A query executed with PDO::query can execute either a prepared statement or directly, depending on the setting of PDO::SQLSRV_ATTR_DIRECT_QUERY. For more information, see Direct Statement Execution and Prepared Statement Execution in the PDO_SQLSRV Driver.

PDO::SQLSRV_ATTR_QUERY_TIMEOUT also affects the behavior of PDO::exec; for more information, see PDO::setAttribute.

You can specify the following options for $fetch_style.

Style	Description
PDO::FETCH_COLUMN, num	Queries for data in the specified column. The first column in the table is column 0.
PDO::FETCH_CLASS, 'classname', array( arglist )	Creates an instance of a class and assigns column names to properties in the class. If the class constructor takes one or more parameters, you can also pass an arglist.
PDO::FETCH_CLASS, 'classname'	Assigns column names to properties in an existing class.

Call PDOStatement::closeCursor to release database resources associated with the PDOStatement object before calling PDO::query again.

You can close a PDOStatement object by setting it to null.

If all the data in a result set is not fetched, the next PDO::query call will not fail.

Support for PDO was added in version 2.0 of the Microsoft Drivers for PHP for SQL Server.

Query example

This example shows several queries.

<?php  
$database = "AdventureWorks";  
$conn = new PDO( "sqlsrv:server=(local) ; Database = $database", "", "");  
$conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );  
$conn->setAttribute( PDO::SQLSRV_ATTR_QUERY_TIMEOUT, 1 );  
  
$query = 'select * from Person.ContactType';  
  
// simple query  
$stmt = $conn->query( $query );  
while ( $row = $stmt->fetch( PDO::FETCH_ASSOC ) ){  
   print_r( $row['Name'] ."\n" );  
}  
  
echo "\n........ query for a column ............\n";  
  
// query for one column  
$stmt = $conn->query( $query, PDO::FETCH_COLUMN, 1 );  
while ( $row = $stmt->fetch() ){  
   echo "$row\n";  
}  
  
echo "\n........ query with a new class ............\n";  
$query = 'select * from HumanResources.Department order by GroupName';  
// query with a class  
class cc {  
   function __construct( $arg ) {  
      echo "$arg";  
   }  
  
   function __toString() {  
      return $this->DepartmentID . "; " . $this->Name . "; " . $this->GroupName;  
   }  
}  
  
$stmt = $conn->query( $query, PDO::FETCH_CLASS, 'cc', array( "arg1 " ));  
  
while ( $row = $stmt->fetch() ){  
   echo "$row\n";  
}  
  
echo "\n........ query into an existing class ............\n";  
$c_obj = new cc( '' );  
$stmt = $conn->query( $query, PDO::FETCH_INTO, $c_obj );  
while ( $stmt->fetch() ){  
   echo "$c_obj\n";  
}  
  
$stmt = null;  
?>

Sql_variant example

This code sample shows how to create a table of sql_variant types and fetch the inserted data.

<?php
$server = 'serverName';
$dbName = 'databaseName';
$uid = 'yourUserName';
$pwd = 'yourPassword';

$conn = new PDO("sqlsrv:server=$server; database = $dbName", $uid, $pwd);
$conn->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );  

try {
    $tableName = 'testTable';
    $query = "CREATE TABLE $tableName ([c1_int] sql_variant, [c2_varchar] sql_variant)";

    $stmt = $conn->query($query);
    unset($stmt);

    $query = "INSERT INTO [$tableName] (c1_int, c2_varchar) VALUES (1, 'test_data')";
    $stmt = $conn->query($query);
    unset($stmt);

    $query = "SELECT * FROM $tableName";
    $stmt = $conn->query($query);

    $result = $stmt->fetch(PDO::FETCH_ASSOC);
    print_r($result);
    
    unset($stmt);
    unset($conn);
} catch (Exception $e) {
    echo $e->getMessage();
}
?>

The expected output would be:

Array
(
    [c1_int] => 1
    [c2_varchar] => test_data
)

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