Question

I’ve been racking my brain on this one, searching all over the place and I cannot find an answer. I’m trying to pull the data from 2 columns of a 14×9 mysql db table and place it into an array. Sounds simple right? I’m trying to use PDO because it is more secure and because I just wanted to learn how it worked. Here is the code:

$anId='id';
$aName='name';

$stmt = $dbh->prepare("SELECT :theid,:thename FROM a_table_in_my_database");
$stmt->bindParam(':theid', $anId);
$stmt->bindParam(':thename', $aName);
$stmt->execute();

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
    print_r($row);
    echo '<br />';
}

‘id’ and ‘name’ are the names of the columns from the table I am trying to select. I am expecting to get something like this:

 Array ( [id] => int1 [name] => stringA )
 Array ( [id] => int2 [name] => stringB )
 Array ( [id] => int3 [name] => stringC )
 Array ( [id] => int4 [name] => stringD )
 Array ( [id] => int5 [name] => stringE )
 Array ( [id] => int6 [name] => stringF )
 Array ( [id] => int7 [name] => stringG )
 Array ( [id] => int8 [name] => stringH )
 Array ( [id] => int9 [name] => stringI )

but instead I am getting this:

 Array ( [id] => id [name] => name )
 Array ( [id] => id [name] => name )
 Array ( [id] => id [name] => name )
 Array ( [id] => id [name] => name )
 Array ( [id] => id [name] => name )
 Array ( [id] => id [name] => name )
 Array ( [id] => id [name] => name )
 Array ( [id] => id [name] => name )
 Array ( [id] => id [name] => name )

It literally says ‘id’ and ‘name’ and not the values.

Any idea what is going on?

Answer 1

$anId and $aName are strings, and because you’re treating them as bing values, PDO is wrapping them in quotes, so your SQL is effectively

SELECT 'id','name' 
 FROM a_table_in_my_database

It’s giving you exactly what you ask for,

DO NOT USE BINDA PARAMS FOR COLUMN NAMES, TABLE NAMES, ETC…. only for data values