如何使用PHP PDO函数提取在SQL事务中获取特定查询的结果？

Question

I have a SQL transaction similar to the one below. I am unable to obtain the result of the 3rd query in the transaction using PHP function PDO::fetch()

$database = DatabaseFactory::getFactory()->getConnection();
$sql = "BEGIN;
        DELETE FROM users WHERE ID = 4;
        UPDATE audit SET nousers= nousers - 1 WHERE ID = 4;
        SELECT nousers FROM audit WHERE ID = 4;
        COMMIT;";
$query = $database->prepare($sql);
$query->execute();

How do I use $query->fetch() to obtain the result of the 3rd query in the transaction?

Answer 1

You have five queries in your transaction, counting BEGIN and COMMIT .

Call prepare() and execute() five times, one for each of the queries. For your SELECT query, retrieve and examine the result set.

There's no need to put all queries of a transaction into a single prepare / execute cycle. The whole point of the transaction is to allow you to run multiple queries so they look like one unitary operation to other clients of the database server.