PDO＃1054“ where”子句中的未知列“ n”

Question

I have a class with a function that will pull out any data from the database whatever the identifying column may be, which basicly looks like this

    use Database\DB;

class General extends DB
{   
    private $fooBar;

    public function getData($column, $table, $value) {
        $column = (array) $column;
        $column = implode(', ', $column);
        $test = $this->query("SELECT `$column` FROM `$table` WHERE $column[0] = :value", array("value" => $value));
    }

}

and is executed as following:

return $this->general->getData(['name'], 'people', 'John Anderson');

However, I'm getting an error which tells me there is an non-existent column input with the value 'n' (which is happening to be the first character of the column name, whatever the column name's value is)

Full error;

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42S22]: Column not found: 1054 Unknown column 'n' in 'where clause'' in a\long\path\DB.class.php on line 50

PDOException: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'n' in 'where clause' in a\long\path\DB.class.php on line 50

Thanks in advance, Jordi

Answer 1

Get rid of the line

$column = implode(', ', $column);

It's replacing the array with a string containing all the column names separated by comma. Then $column[0] will be the first character of the first column name, instead of the first column name.

Answer 2

Put down your full query here.. Than it's easier!

Edit:

try this code:

use Database\DB;

class General extends DB
{   
    private $fooBar;

    public function getData($column, $table, $value) {
        $columns = (array) $column;
        $column = implode(', ', $columns);
        $test = $this->query("SELECT `$column` FROM `$table` WHERE $columns[0] = :value", array("value" => $value));
    }

}

I changed the following: $column = (array) $column; to $columns = (array) $column;

And

SELECT `$column` FROM `$table` WHERE $column[0] = :value", array("value" => $value)

to

SELECT `$column` FROM `$table` WHERE $columns[0] = :value", array("value" => $value)

Answer 3

This should fix it (see @Barmar answer as well):

(Take note of the difference in the implode statement as well).

use Database\DB;

class General extends DB
{   
    private $fooBar;

    public function getData($column, $table, $value) {
        $column = (array) $column;
        $whereCol = $column[0];
        $column = implode('`, `', $column);
        $test = $this->query("SELECT `$column` FROM `$table` WHERE $whereCol = :value", array("value" => $value));

        return $test;
    }

}