PHP + PDO: Bind null if param is empty

问题

I'm trying this (and all PoST var are treated before user send it, no SQL Injection worries):

$stmt = $con->prepare($sql);
$stmt->bindParam(":1", $this->getPes_cdpessoa());
$stmt->bindParam(":2", $this->getPdf_nupessoa_def());

When any of those vars are NULL, PDO cries and don't let execute my statement, and on my Table, i DO allow these fields beign nullables.

Is there any way to check if the values are empty, pdo just bind NULL to then (and i mean, a smart way instead if(empty($_POST['blablabla')...) for every single param?

回答1:

Try:

$stmt = $con->prepare($sql);
$stmt->bindParam(':1', $this->getPes_cdpessoa(), PDO::PARAM_NULL);
$stmt->bindParam(":2", $this->getPdf_nupessoa_def(), PDO::PARAM_NULL);

Also, see:

• How do I insert NULL values using PDO?

回答2:

bindParam needs an actual variable to be passed to it, because it creates a reference. So, when your functions return null, bindParam doesn't really have anything valid to do.

You need to use bindValue instead. Note that bindValue will immediately use whatever value you pass to it, where bindParam waits until statement execution to actually retrieve the values to use.

回答3:

The Alternative syntax works:

$stmt = $con->prepare($sql);
$stmt->execute(array($this->getPes_cdpessoa(), $this->getPdf_nupessoa_def()));

来源：https://stackoverflow.com/questions/3587034/php-pdo-bind-null-if-param-is-empty