使用PHP中的PDO基于主键读取MySQL数据库

Question

My code doesn't seem to work. I'm using the following:

$statement   = $db->prepare("SELECT * FROM carts WHERE (order_id = ':order_id')");
$result      = $statement->execute(array(':order_id' => $order_id));
$result      = $statement->fetch(); 

Which returns a boolean according to gettype($result); print_r($result) simply displays Array, though this is not expected. The data I'm reading is:

So I should expect an Array to be returned, not a Boolean. The PDO is correct and working, as I can call a write command. What's the best way using PDO to read a row based on the Primary Key order_id into a parsable array?

And as a split, is there a more efficient way than SELECT * WHERE to read a single row of data from a TABLE when the data is based on the Primary Key?

Answer 1

before all, set properly your error mode. If you can run the query with single quotes without an error popping, set this:

$db->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);
$statement = $db->prepare("SELECT * FROM carts WHERE order_id=:order_id");
$result = $statement->execute(array(':order_id' => $order_id));
$row = ($result ? $statement->fetch(PDO::FETCH_ASSOC) : array('problem' => 'with your query'));
print_r($result);

PDO fails with single-quotes around parameters. check your $result for the return value of execute(). you may have to specify a fetching mode for the fetch. depending on your sql database, parenthesis around the condition may also cause the query to fail.