(PHP 5 >= 5.1.0, PECL pdo:0.9-1.0.3)
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.
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 in the next row of a result set.
There is no way to return another column from the same row if you use PDOStatement->fetchColumn() to retrieve data.
Example#1 Return first column of the next row
<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
/* Fetch the first column from the next row in the result set */
print("Fetch the first column from the next row in the result set:\n");
$result = $sth->fetchColumn();
print("name = $result\n");
print("Fetch the second column from the next row in the result set:\n");
$result = $sth->fetchColumn(1);
print("colour = $result\n");
?>
上例将输出：
Fetch the first column from the next row in the result set: name = lemon Fetch the second column from the next row in the result set: colour = red