PDO - can you handle identical prepared statements?

December 1st, 2008 by Aaron

I’ve been wondering if I should be concerned about re-preparing a prepared statement when using PDO. Right now, I use code like this when preparing a statement:

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	public function prep($statement)
	{
		if ($statement != $this->_lastPrepared) {
			/**
			 * Store our clear text statement, and then our object
			 */
			$this->_lastPrepared = $statement;
			$this->_ps = $this->db->prepare($statement);
		}
	}

I end up storing the last statement and do a quick compare. My concern comes from MySQL’s admission of this:
“If a prepared statement with the given name already exists, it is deallocated implicitly before the new statement is prepared.”

So, not knowing the internal workings of PDO, I wonder how they handle it. Do they…

• Create each prepared statement with the same name, causing them to be deallocated each time
• Create each one with a random name, so that there are never any deallocations unless you unset the statement?

Anyone have any insight?