PDOStatement::fetchColumn

(PHP 5 >= 5.1.0, PHP 7, PECL pdo >= 0.9.0)

PDOStatement::fetchColumn Returns a single column from the next row of a result set

Descrierea

public PDOStatement::fetchColumn ([ int $column_number = 0 ] ) : mixed

Returns a single column from the next row of a result set or false if there are no more rows.

Notă:

PDOStatement::fetchColumn() should not be used to retrieve boolean columns, as it is impossible to distinguish a value of false from there being no more rows to retrieve. Use PDOStatement::fetch() instead.

Parametri

column_number

0-indexed number of the column you wish to retrieve from the row. If no value is supplied, PDOStatement::fetchColumn() fetches the first column.

Valorile întoarse

PDOStatement::fetchColumn() returns a single column from the next row of a result set or false if there are no more rows.

Avertizare

There is no way to return another column from the same row if you use PDOStatement::fetchColumn() to retrieve data.

Exemple

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");
?>

Exemplul de mai sus va afișa:

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

A se vedea și

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User Contributed Notes 2 notes

up
53
PhoneixSegovia at GOOGLE_MAIL_SERVER dot com
13 years ago
fetchColumn return boolean false when a row not is found or don't had more rows.
up
12
seanferd at assmasterdonkeyranch dot com
17 years ago
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->query('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.
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