PDO
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PDO::query

(PHP 5 >= 5.1.0, PECL pdo >= 0.2.0)

PDO::query — Executes an SQL statement, returning a result set as a PDOStatement object

说明

PDOStatement PDO::query ( string $statement )
PDOStatement PDO::query ( string $statement , int $PDO::FETCH_COLUMN , int $colno )
PDOStatement PDO::query ( string $statement , int $PDO::FETCH_CLASS , string $classname , array $ctorargs )
PDOStatement PDO::query ( string $statement , int $PDO::FETCH_INTO , object $object )

PDO::query() executes an SQL statement in a single function call, returning the result set (if any) returned by the statement as a PDOStatement object.

For a query that you need to issue multiple times, you will realize better performance if you prepare a PDOStatement object using PDO::prepare() and issue the statement with multiple calls to PDOStatement::execute().

If you do not fetch all of the data in a result set before issuing your next call to PDO::query(), your call may fail. Call PDOStatement::closeCursor() to release the database resources associated with the PDOStatement object before issuing your next call to PDO::query().

Note: Although this function is only documented as having a single parameter, you may pass additional arguments to this function. They will be treated as though you called PDOStatement::setFetchMode() on the resultant statement object.

参数

statement

The SQL statement to prepare and execute.

返回值

PDO::query() returns a PDOStatement object.

范例

Example #1 Demonstrate PDO::query

A nice feature of PDO::query() is that it enables you to iterate over the rowset returned by a successfully executed SELECT statement.

<?php
function getFruit($conn) {
    $sql = 'SELECT name, colour, calories FROM fruit ORDER BY name';
    foreach ($conn->query($sql) as $row) {
        print $row['NAME'] . "\t";
        print $row['COLOUR'] . "\t";
        print $row['CALORIES'] . "\n";
    }
}
?>

上例将输出：

apple   red     150
banana  yellow  250
kiwi    brown   75
lemon   yellow  25
orange  orange  300
pear    green   150
watermelon      pink    90

参见

PDO
PHP 手册