PDOStatement::fetch --
Fetches the next row from a result set
Description
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.
Parameters
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.
Examples
Example 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 $result->NAME; print("\n"); ?>
The above example will output:
PDO::FETCH_ASSOC: Return next row as an array indexed by column name
Array
(
[NAME] => apple
[COLOUR] => red
)
PDO::FETCH_BOTH: Return next row as an array indexed by both column name and number
Array
(
[NAME] => banana
[0] => banana
[COLOUR] => yellow
[1] => yellow
)
PDO::FETCH_LAZY: Return next row as an anonymous object with column names as properties
PDORow Object
(
[NAME] => orange
[COLOUR] => orange
)
PDO::FETCH_OBJ: Return next row as an anonymous object with column names as properties
kiwi
Example 2. Fetching rows with a scrollable cursor
<?php function readDataForwards($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(); } }
