Question

Suppose I have a very large array of information for a user:

$user=array(
"name"=>"john",
"ip"=>"xx.xx.xx.xx",
"email"=>"[e-mail]",
//lots more values
)

Let’s also suppose that this information needs to go into more than one table. For instance a username needs to go table users, address needs to go into a details table, etc.

Now, I use a certain self-made function to insert into my tables that matches array keys to column names and array values to the values being inputted. Something similar to this:

function insert_sql($table, arr $values){
    GLOBAL $dbc;
    $sql="INSERT INTO `$table` (".implode(array_keys($values), ", ").") VALUES (".implode(array_values($values), ", ").")";
    $dbc->prepare($sql)->execute();
    return $dbc->lastInsertId();

}
//I don't actually use this function, just trying to show you what is being accomplished.

The problem is that my function uses all the keys and all the values, so when I just need certain parts of the array put into multiple tables, it doesn’t work.

The question is:

How do I make an INSERT statement ignore a column if it doesn’t exist? So if I insert name,email,address, into table users, but this table doesn’t have an address column, I need it to insert the row with the name and email but simply ignore the fact that the address column is not there.

EDIT: The other option is to make an array with the columns of a table and use it to filter the values array. Although I am not really sure how to set this up.

Answer 1

Find given table column names:

SELECT 
column_name
FROM 
information_schema.columns
WHERE 
table_name =  'tablename'

And then just whitelist your keys in $values array

Example:

function insert_sql($table, array $values){
        global $connection;
        $query = "SELECT column_name FROM information_schema.columns WHERE table_name =  :tablename";
        /* @var $stmt PDOStatement */
        $stmt  = $connection->prepare($query);
        $stmt->execute(array(
            'tablename' => $table
        ));
        $columns = array_flip($stmt->fetchAll(PDO::FETCH_COLUMN, 0));
        $values  = array_intersect_key($values, $columns);
        var_dump($values);
    }