International PHP Conference 2015

PDOStatement::closeCursor

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

PDOStatement::closeCursor Closes the cursor, enabling the statement to be executed again.

Descrierea

public bool PDOStatement::closeCursor ( void )

PDOStatement::closeCursor() frees up the connection to the server so that other SQL statements may be issued, but leaves the statement in a state that enables it to be executed again.

This method is useful for database drivers that do not support executing a PDOStatement object when a previously executed PDOStatement object still has unfetched rows. If your database driver suffers from this limitation, the problem may manifest itself in an out-of-sequence error.

PDOStatement::closeCursor() is implemented either as an optional driver specific method (allowing for maximum efficiency), or as the generic PDO fallback if no driver specific function is installed. The PDO generic fallback is semantically the same as writing the following code in your PHP script:

<?php
do {
    while (
$stmt->fetch())
        ;
    if (!
$stmt->nextRowset())
        break;
} while (
true);
?>

Valorile întoarse

Întoarce valoarea TRUE în cazul succesului sau FALSE în cazul eșecului.

Exemple

Example #1 A PDOStatement::closeCursor() example

In the following example, the $stmt PDOStatement object returns multiple rows but the application fetches only the first row, leaving the PDOStatement object in a state of having unfetched rows. To ensure that the application will work with all database drivers, the author inserts a call to PDOStatement::closeCursor() on $stmt before executing the $otherStmt PDOStatement object.

<?php
/* Create a PDOStatement object */
$stmt $dbh->prepare('SELECT foo FROM bar');

/* Create a second PDOStatement object */
$otherStmt $dbh->prepare('SELECT foobaz FROM foobar');

/* Execute the first statement */
$stmt->execute();

/* Fetch only the first row from the results */
$stmt->fetch();

/* The following call to closeCursor() may be required by some drivers */
$stmt->closeCursor();

/* Now we can execute the second statement */
$otherStmt->execute();
?>

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User Contributed Notes 4 notes

up
1
Anonymous
2 months ago
In case this is helpful to anybody else who ends-up here after getting the following error:

SQLState: 24000 [Microsoft][ODBC SQL Server Driver]Invalid cursor state

PDOStatement :: closeCursor() did not fix the issue for me. However, adding SET NOCOUNT ON to the beginning of my stored procedure did.
up
0
jhill9693 at gmail dot com
4 years ago
If you ran a SQL statement (vs a query that returns data) such as UPDATE, try unsetting your PDOStatement object instead of calling PDOStatement::closeCursor().
up
-1
Anonymous
2 months ago
At least with MySQL this function also resets any bound columns, so the fetches will go through as expected but you will be getting stale data in the loop.

Redo all the binds before continuing!
up
-3
narada dot sage at googlemail dot com
9 years ago
When running multiple queries one after another especially when stored procedures are involved one must release all result sets and fetch all rows in each result set for a stored procedure before moving onto the next query.  This is important because a stored procedure returns an extra (empty) result set as a result of having called the procedure itself.

In my case calling PDOStatement :: closeCursor() did not work (on php-5.1.3-rc2) and I was presented with the following error message: "SQLSTATE[HY000]: General error: 2013 Lost connection to MySQL server during query" upon trying to PDO :: prepare() my second query.  So I used the following drop in replacement within one of my classes which fixed the issue.

<?php
/**
* @param PDOStatement $oStm
*/
public static function closeCursor($oStm) {
    do
$oStm->fetchAll();
    while (
$oStm->nextRowSet());
}
?>
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