Question

I am attempting to UPDATE records within my MySQL database.

I build the prepared statement using arrays / loops:

$sql =  "UPDATE table01 SET ";  
        foreach($values as $value)
        {
        $sql .="$value = :$value, ";
        }
        $sql = rtrim($sql,', ');    
        $sql .=" WHERE id = '$id'";

then I prepare this statement:

try 
{
$pdo = new PDO('mysql:host=localhost; dbname=db01', $username, $password);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$stmt = $pdo->prepare($sql);

Then I bind each of the tokens / placeholders in the prepared statement to the values to be inserted using another loop:

foreach(array_combine($values, $variables) as $value=>$variable)
{
$stmt->bindParam(':$value', $variable);
}

$stmt->execute();         

where $values is an array of column headers in the database (therefore ‘:$value’ is a set of token names corresponding to them) and $variables is an array of variables containing data to be stored.

When I run this, I am given the error:

Error: SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens

But as you can see I’m forming them from arrays – I’ve done counts on the arrays to ensure the elements match 1:1 and they do:

FYI:

$count1 = count($values);
$count2 = count($variables);

echo $count1;
echo $count2;

gives:
7575

(they both have 75 elements in them)

Answer 1

Single quotes don’t interpolate variables.

$stmt->bindParam(':$value', $variable);

should be

$stmt->bindParam(":$value", $variable);