PEAR Справочное руководство
Пред.		След.

DB_common::getOne()

DB_common::getOne() -- Runs a query and returns the first column of the first row

Synopsis

mixed &getOne (string $query [, mixed $params = array()])

Описание

Runs the query provided and returns the data from the first column of the first row then frees the result set.

Параметр

string $query

the SQL query or the statement to prepare

mixed $params

array, string or numeric data to be added to the prepared statement. Quantity of items passed must match quantity of placeholders in the prepared statement: meaning 1 placeholder for non-array parameters or 1 placeholder per array element.

If supplied, prepare()/ execute() is used.

Возвращаемое значение

mixed - the first column's data or a DB_Error object on failure

Throws

Таблица 34-1. Возможные значения PEAR_Error

Error code	Error message	Reason	Solution
`DB_ERROR_INVALID`	invalid	SQL statment for preparing is not valid.	See the prepare() documentation, if you want to use a SQL statemt using placeholders.
`DB_ERROR_MISMATCH`	mismatch	Quantity of parameters didn't match quantity of placeholders in the prepared statment.	Check that the number of placeholders in the prepare() statement passed to `$query` equals the count of entries passed to `$params`.
`DB_ERROR_NODBSELECTED`	no database selected	No database was choosen.	Check the DSN in connect().
every other error code		Database specific error	Check the database related section of PHP-Manual to detect the reason for this error. In the most cases a misformed SQL statment. Ie. using LIMIT in a SQL-Statment for an Oracle database.

Заметка

Эта функция не должна вызываться статически.

Пример

Пример 34-1. Using getOne()

<?php
// Once you have a valid DB object named $db...
$data =& $db->getOne('SELECT cf FROM foo');

if (PEAR::isError($data)) {
    die($data->getMessage());
}

echo "$data\n";
?>

Пример 34-2. Using getOne() with one placeholder

<?php
// Once you have a valid DB object named $db...
$data =& $db->getOne('SELECT cf FROM foo WHERE nf = ?',
        5);

if (PEAR::isError($data)) {
    die($data->getMessage());
}

echo "$data\n";
?>

Пример 34-3. Using getOne() with two placeholders

<?php
// Once you have a valid DB object named $db...
$data =& $db->getOne('SELECT cf FROM foo WHERE nf IN (?, ?)',
        array(5, 10));

if (PEAR::isError($data)) {
    die($data->getMessage());
}

echo "$data\n";
?>

См. также

getRow(), getCol(), getAssoc(), getAll(), query(), "Intro - Prepare & Execute"

Пред.	Начало	След.
DB_common::getListOf()	Уровень выше	DB_common::getOption()

HIVE: All information for read only. Please respect copyright!