PDOStatement::closeCursor
PDOStatement::closeCursor — Closes the cursor so that the statement can be executed again. (PHP 5 >= 5.1.0, PECL pdo >= 0.9.0)
illustrate
grammar
bool PDOStatement::closeCursor ( void )
PDOStatement::closeCursor()Release the connection to the database service to issue other SQL statements, but put the statement in a state that can be executed again.
This method is useful for database drivers that do not support executing another PDOStatement object when there are still unfetched rows in the previous executed PDOStatement object. If the database driver is restricted by this, there may be an out-of-order error problem.
PDOStatement::closeCursor()Either a unique method of optional drivers (most efficient) to implement, or as a general PDO backup when there is no driver-specific functionality. The general alternate semantics are the same as the following PHP code:
<?php
do {
while ($stmt->fetch())
;
if (!$stmt->nextRowset())
break;
} while (true);
?>
Return value
Returns TRUE on success or FALSE on failure.
Example
An example of PDOStatement::closeCursor()
In the following example, the $stmt PDOStatement object returns multiple rows, but the application only takes the first row, leaving the PDOStatement object in a state with unchecked rows. To ensure that the application can run normally on all database drivers, $stmt is called once before executing the $otherStmt PDOStatement object.PDOStatement::closeCursor()。
<?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();
/* Only the first line is taken from the result set */
$stmt->fetch();
/* The following call to closeCursor() may be required by some drivers */
$stmt->closeCursor();
/* The second statement can now be executed */
$otherStmt->execute();
?>
Summarize
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