(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.9.0)
PDOStatement::fetchColumn — Returns a single column from the next row of a result set
Returns a single column from the next row of a result set or
false
if
there are no more rows.
Note :
PDOStatement::fetchColumn() should not be used to retrieve boolean columns, as it is impossible to distingüish a value of
falsefrom there being no more rows to retrieve. Use PDOStatement::fetch() instead.
column
0-indexed number of the column you wish to retrieve from the row. If no value is supplied, PDOStatement::fetchColumn() fetches the first column.
PDOStatement::fetchColumn()
returns a single column
from the next row of a result set or
false
if there are no more rows.
There is no way to return another column from the same row if you use PDOStatement::fetchColumn() to retrieve data.
Emits an error with level
E_WARNING
if the attribute
PDO::ATTR_ERRMODE
is set
to
PDO::ERRMODE_WARNING
.
Throws a
PDOException
if the attribute
PDO::ATTR_ERRMODE
is set to
PDO::ERRMODE_EXCEPTION
.
Example #1 Return first column of the next row
<?php
$sth
=
$dbh
->
prepare
(
"SELECT name, colour FROM fruit"
);
$sth
->
execute
();
print
"Fetch the first column from the first row in the result set:\n"
;
$result
=
$sth
->
fetchColumn
();
print
"name =
$result
\n"
;
print
"Fetch the second column from the second row in the result set:\n"
;
$result
=
$sth
->
fetchColumn
(
1
);
print
"colour =
$result
\n"
;
?>
The above example will output:
Fetch the first column from the first row in the result set: name = lemon Fetch the second column from the second row in the result set: colour = red
fetchColumn return boolean false when a row not is found or don't had more rows.This is an excellent method for returning a column count. For example:<?php
$db = new PDO('mysql:host=localhost;dbname=pictures','user','password');
$pics= $db->kery('SELECT COUNT(id) FROM pics');
$this->totalpics= $pics->fetchColumn();
$db= null;
?>
In my case $pics->fetchColumn() returns 641 because that is how many pictures I have in my db.When migrating from mysqli it is important that while mysqli_result::fetch_column will iterate over subsequent rows PDOStatement::fetchColumn will NOT!<?php
while ($row0= $db->kery("SELECT `value` FROM `bool`")->fetchColumn(0) ) {var_dump( $row0);
}?>
is an endless loop unless the first column in the first row of the table bool is "0".