PDOStatement::fetchAll

Returns an array containing all of the result set rows

&reftitle.description; public `array` `PDOStatement::fetchAll` `int` `fetch_style` `mixed` `fetch_argument` `array` `ctor_args` array()
&reftitle.parameters;

`fetch_style`

- Controls the contents of the returned array as documented in `PDOStatement::fetch`. Defaults to value of `PDO::ATTR_DEFAULT_FETCH_MODE` (which 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`. You can specify which column you want with the `column-index` parameter.

  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`.

`fetch_argument`

- This argument have a different meaning depending on the value of the `fetch_style` parameter:

  - `PDO::FETCH_COLUMN`: Returns the indicated 0-indexed column.

  - `PDO::FETCH_CLASS`: Returns instances of the specified class, mapping the columns of each row to named properties in the class.

  - `PDO::FETCH_FUNC`: Returns the results of calling the specified function, using each row's columns as parameters in the call.

`ctor_args`

- Arguments of custom class constructor when the `fetch_style` parameter is `PDO::FETCH_CLASS`.

&reftitle.returnvalues;

`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. An empty array is returned if there are zero results to fetch, or &false; on failure.

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 ORDER BY clauses in SQL to restrict results before retrieving and processing them with PHP.

&reftitle.examples;

### 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);
    ?>

&example.outputs.similar;

    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
            )

    )

### 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);
    ?>

&example.outputs.similar;

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

### 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(array('apple', 'green'));
    $insert->execute(array('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));
    ?>

&example.outputs.similar;

    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"
      }
    }

### Instantiating a class for each result

The following example demonstrates the behaviour of the `PDO::FETCH_CLASS` fetch style.

    <?php
    class fruit {
        public $name;
        public $colour;
    }

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

    $result = $sth->fetchAll(PDO::FETCH_CLASS, "fruit");
    var_dump($result);
    ?>

&example.outputs.similar;

    array(3) {
      [0]=>
      object(fruit)#1 (2) {
        ["name"]=>
        string(5) "apple"
        ["colour"]=>
        string(5) "green"
      }
      [1]=>
      object(fruit)#2 (2) {
        ["name"]=>
        string(4) "pear"
        ["colour"]=>
        string(6) "yellow"
      }
      [2]=>
      object(fruit)#3 (2) {
        ["name"]=>
        string(10) "watermelon"
        ["colour"]=>
        string(4) "pink"
      }
    }

### Calling a function for each result

The following example demonstrates the behaviour of the `PDO::FETCH_FUNC` fetch style.

    <?php
    function fruit($name, $colour) {
        return "{$name}: {$colour}";
    }

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

    $result = $sth->fetchAll(PDO::FETCH_FUNC, "fruit");
    var_dump($result);
    ?>

&example.outputs.similar;

    array(3) {
      [0]=>
      string(12) "apple: green"
      [1]=>
      string(12) "pear: yellow"
      [2]=>
      string(16) "watermelon: pink"
    }

&reftitle.seealso;

- `PDO::query`
- `PDOStatement::fetch`
- `PDOStatement::fetchColumn`
- `PDO::prepare`
- `PDOStatement::setFetchMode`