'PDOException' with message 'SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active

Question

I know this question has been asked many times, but the commonly-accepted answers didn\'t help me. But quite by accident I stumbled on an answer.

Here\'s the setup: I h

Answer 1

Trigger can be created via PDO::exec() even when PDO::ATTR_EMULATE_PREPARES = false:

setAttribute (PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$db->setAttribute (PDO::ATTR_EMULATE_PREPARES, false);
$db->setAttribute (PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true);

$db->exec("CREATE TRIGGER `CirclesClosureSync` AFTER INSERT ON Circles
FOR EACH ROW BEGIN
    INSERT INTO CirclesClosure (ancestor, descendant) 
    SELECT ancestor, NEW.ID from CirclesClosure WHERE descendant=NEW.Parent;
    INSERT INTO CirclesClosure (ancestor, descendant) values (NEW.ID, NEW.ID);
END;");