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Podręcznik PHP
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PDOStatement::fetch

(no version information, might be only in CVS)

PDOStatement::fetch -- Fetches the next row from a result set

Opis

mixed PDOStatement::fetch ( [int fetch_style [, int cursor_orientation [, int cursor_offset]]] )

Fetches a row from a result set associated with a PDOStatement object. The fetch_style parameter determines how PDO returns the row.

Parametry

fetch_style

Controls how the next row will be returned to the caller. This value must be one of the PDO::FETCH_* constants, defaulting to PDO::FETCH_BOTH.

PDO::FETCH_ASSOC: returns an array indexed by column name as returned in your result set
PDO::FETCH_BOTH (default): returns an array indexed by both column name and 0-indexed column number as returned in your result set
PDO::FETCH_BOUND: returns TRUE and assigns the values of the columns in your result set to the PHP variables to which they were bound with the PDOStatement::bindParam() method
PDO::FETCH_CLASS: returns a new instance of the requested class, mapping the columns of the result set to named properties in the class. If fetch_style includes PDO::FETCH_CLASSTYPE (e.g. PDO::FETCH_CLASS | PDO::FETCH_CLASSTYPE) then the name of the class is determined from a value of the first column.
PDO::FETCH_INTO: updates an existing instance of the requested class, mapping the columns of the result set to named properties in the class
PDO::FETCH_LAZY: combines PDO::FETCH_BOTH and PDO::FETCH_OBJ, creating the object variable names as they are accessed
PDO::FETCH_NUM: returns an array indexed by column number as returned in your result set, starting at column 0
PDO::FETCH_OBJ: returns an anonymous object with property names that correspond to the column names returned in your result set

cursor_orientation

For a PDOStatement object representing a scrollable cursor, this value determines which row will be returned to the caller. This value must be one of the PDO::FETCH_ORI_* constants, defaulting to PDO::FETCH_ORI_NEXT. To request a scrollable cursor for your PDOStatement object, you must set the PDO::ATTR_CURSOR attribute to PDO::CURSOR_SCROLL when you prepare the SQL statement with PDO::prepare().

offset

For a PDOStatement object representing a scrollable cursor for which the cursor_orientation parameter is set to PDO::FETCH_ORI_ABS, this value specifies the absolute number of the row in the result set that shall be fetched.

For a PDOStatement object representing a scrollable cursor for which the cursor_orientation parameter is set to PDO::FETCH_ORI_REL, this value specifies the row to fetch relative to the cursor position before PDOStatement::fetch() was called.

Przykłady

Przykład 1. Fetching rows using different fetch styles

<?php

                $sth = $dbh->prepare("SELECT name, colour FROM fruit");

                $sth->execute();

                
/* Exercise PDOStatement::fetch styles */

                print("PDO::FETCH_ASSOC: ");


                print("Return next row as an array indexed by column name\n");

                $result = $sth->fetch(PDO::FETCH_ASSOC);
print_r($result);

                print("\n");

                

                print("PDO::FETCH_BOTH: ");


                print("Return next row as an array indexed by both column name and number\n");

                $result = $sth->fetch(PDO::FETCH_BOTH);
print_r($result);

                print("\n");

                

                print("PDO::FETCH_LAZY: ");


                print("Return next row as an anonymous object with column names as properties\n");

                $result = $sth->fetch(PDO::FETCH_LAZY);
print_r($result);

                print("\n");

                

                print("PDO::FETCH_OBJ: ");


                print("Return next row as an anonymous object with column names as properties\n");

                $result = $sth->fetch(PDO::FETCH_OBJ);

                print $result->NAME;

                print("\n");
?>

Powyższy przykład wyświetli:

PDO::FETCH_ASSOC: Return next row as an array indexed by column name
Array
(
    [NAME] => apple
    [COLOUR] => red
)

PDO::FETCH_BOTH: Return next row as an array indexed by both column name and number
Array
(
    [NAME] => banana
    [0] => banana
    [COLOUR] => yellow
    [1] => yellow
)

PDO::FETCH_LAZY: Return next row as an anonymous object with column names as properties
PDORow Object
(
    [NAME] => orange
    [COLOUR] => orange
)

PDO::FETCH_OBJ: Return next row as an anonymous object with column names as properties
kiwi

Przykład 2. Fetching rows with a scrollable cursor

<?php
function readDataForwards($dbh) {


                  $sql = 'SELECT hand, won, bet FROM mynumbers ORDER BY BET';


                  try {

                    $stmt = $dbh->prepare($sql, array(PDO::ATTR_CURSOR, PDO::CURSOR_SCROLL));

                    $stmt->execute();

                    while ($row = $stmt->fetch(PDO::FETCH_NUM, PDO::FETCH_ORI_NEXT)) {

                      $data = $row[0] . "\t" . $row[1] . "\t" . $row[2] . "\n";

                      print $data;

                    }

                    $stmt = null;

                  }

                  catch (PDOException $e) {

                    print $e->getMessage();

                  }

                }

                function readDataBackwards($dbh) {


                  $sql = 'SELECT hand, won, bet FROM mynumbers ORDER BY bet';


                  try {

                    $stmt = $dbh->prepare($sql, array(PDO::ATTR_CURSOR, PDO::CURSOR_SCROLL));

                    $stmt->execute();

                    $row = $stmt->fetch(PDO::FETCH_NUM, PDO::FETCH_ORI_LAST);

                    do {

                      $data = $row[0] . "\t" . $row[1] . "\t" . $row[2] . "\n";

                      print $data;

                    } while ($row = $stmt->fetch(PDO::FETCH_NUM, PDO::FETCH_ORI_PRIOR));

                    $stmt = null;

                  }

                  catch (PDOException $e) {

                    print $e->getMessage();

                  }

                }

                

                print "Reading forwards:\n";

                readDataForwards($conn);


                

                print "Reading backwards:\n";

                readDataBackwards($conn);

                ?>

Powyższy przykład wyświetli:

Reading forwards:
21    10    5
16    0     5
19    20    10

Reading backwards:
19    20    10
16    0     5
21    10    5

Patrz także

PDO::query()

PDOStatement::fetchAll()

PDOStatement::fetchColumn()

PDOStatement::prepare()

PDOStatement::setFetchMode()

Poprzedni	Spis treści	Następny
PDOStatement::execute	Początek rozdziału	PDOStatement::fetchAll