using an empty array as a parameter for execute

Question

I was reader about PDO , and I was wondering what is the deference between those two methods:

public function query($sql)
    {
        $req = $this->db->prepare($sql);
        $req->execute();
        return $req->fetchAll(PDO::FETCH_OBJ);
    }

public function query($sql, $data  = array())
    {
        $req = $this->db->prepare($sql);
        $req->execute($data);
        return $req->fetchAll(PDO::FETCH_OBJ);
    }

In the second method, execute has an empty array as a parameter and the first one doesn't, what is the role of using an empty array as a parameter for execute ?

people can always pass second parameter in second query() function, I can't understand much from this piece of code... — Prashank
– Prashank, Commented Mar 17, 2013 at 13:58
Did you post this question after reading the documentation page? It lists there what are the arguments for the method. Maybe something was not clear from there? — Burhan Khalid
– Burhan Khalid, Commented Mar 17, 2013 at 14:00

Lix · Accepted Answer · 2013-03-17 13:59:23Z

1

The array is only empty by default. You can pass values in that array and they will be inserted into your SQL statement appropriately (ie - array key=>field name).

Defining an empty array in the function parameters states that this is an optional parameter and you are not forced to pass it - only when it is relevant. For example, when performing an INSERT command. If you don't pass any value to the $data parameter, it's default value will simply be an empty array.

An example of using default parameters -

function saySomething($text="Hello World!"){
  echo $text;
}

saySomething(); // will echo out the default "Hello World!"
saySomething("Goodbye World!"); // will echo out "Goodbye World!" as specified.

answered Mar 17, 2013 at 13:59

Lix

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Your Common Sense · Accepted Answer · 2013-03-17 14:07:10Z

1

First one lets you to run a query without parameters.
Second one lets you to run a query either with parameters or without:

$data = $db->query("SELECT * FROM table"); 
$data = $db->query("SELECT * FROM table WHERE id=?",array($id));

both works.

answered Mar 17, 2013 at 14:07

Your Common Sense

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xdbas · Accepted Answer · 2017-07-26 12:38:04Z

1

You can add you parameter bindings in an array instead of using the bindParam() function beforehand.

for instance you wanna select something by id

    $stmt = $dbh->prepare("SELECT * FROM `something` WHERE `id` = ?");
    $stmt->execute(array($id));

is the same as

    $stmt = $dbh->prepare("SELECT * FROM `something` WHERE `id` = ?");
    $stmt->bindParam(1, $id, PDO::PARAM_INT, 11);
    $stmt->execute();

Though for the bindParam function you can check better, Check PHP Manual PDO::excute()

edited Jul 26, 2017 at 12:38

answered Mar 17, 2013 at 13:57

xdbas

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