PDOStatement::fetchAll

(no version information, might be only in CVS)

PDOStatement::fetchAll --  Returns an array containing all of the result set rows

说明

array PDOStatement::fetchAll ( [int fetch_style [, int column_index]] )

参数

fetch_style

Controls the contents of the returned array as documented in PDOStatement::fetch(). Defaults to PDO_FETCH_BOTH.

To return an array consisting of all values of a single column from the result set, specify PDO_FETCH_COLUMN.

To fetch only the unique values of a single column from the result set, bitwise-OR PDO_FETCH_COLUMN with PDO_FETCH_UNIQUE.

To return an associative array grouped by the values of a specified column, bitwise-OR PDO_FETCH_COLUMN with PDO_FETCH_GROUP.

column_index

Returns the indicated 0-indexed column when the value of fetch_style is PDO_FETCH_COLUMN. Defaults to 0.

返回值

PDOStatement::fetchAll() returns an array containing all of the remaining rows in the result set. The array represents each row as either an array of column values or an object with properties corresponding to each column name.

Using this method to fetch large result sets will result in a heavy demand on system and possibly network resources. Rather than retrieving all of the data and manipulating it in PHP, consider using the database server to manipulate the result sets. For example, use the WHERE and SORT BY clauses in SQL to restrict results before retrieving and processing them with PHP.

范例

例子 1. Fetch all remaining rows in a result set

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

/* Fetch all of the remaining rows in the result set */
print("Fetch all of the remaining rows in the result set:\n");
$result = $sth->fetchAll();
print_r($result);
?>

上例将输出:

Fetch all of the remaining rows in the result set:
Array
(
    [0] => Array
        (
            [NAME] => pear
            [0] => pear
            [COLOUR] => green
            [1] => green
        )

    [1] => Array
        (
            [NAME] => watermelon
            [0] => watermelon
            [COLOUR] => pink
            [1] => pink
        )

)

例子 2. Fetching all values of a single column from a result set

The following example demonstrates how to return all of the values of a single column from a result set, even though the SQL statement itself may return multiple columns per row.

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

/* Fetch all of the values of the first column */
$result = $sth->fetchAll(PDO_FETCH_COLUMN, 0);
var_dump($result);
?>

上例将输出:

Array(3)
(
    [0] =>
    string(5) => apple
    [1] =>
    string(4) => pear
    [2] =>
    string(10) => watermelon
)

例子 3. Grouping all values by a single column

The following example demonstrates how to return an associative array grouped by the values of the specified column in the result set. The array contains three keys: values apple and pear are returned as arrays that contain two different colours, while watermelon is returned as an array that contains only one colour.

<?php
$insert
= $dbh->prepare("INSERT INTO fruit(name, colour) VALUES (?, ?)");
$insert->execute('apple', 'green');
$insert->execute('pear', 'yellow');

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

/* Group values by the first column */
var_dump($sth->fetchAll(PDO_FETCH_COLUMN|PDO_FETCH_GROUP));
?>

上例将输出:

array(3) {
  ["apple"]=>
  array(2) {
    [0]=>
    string(5) "green"
    [1]=>
    string(3) "red"
  }
  ["pear"]=>
  array(2) {
    [0]=>
    string(5) "green"
    [1]=>
    string(6) "yellow"
  }
  ["watermelon"]=>
  array(1) {
    [0]=>
    string(5) "green"
  }
}

参见

PDO::query()
PDOStatement::fetch()
PDOStatement::fetchColumn()
PDOStatement::prepare()
PDOStatement::setFetchMode()