“Unknown column in 'field list'”, but column does exist

Question

DROP TABLE IF EXISTS `transactions`;
CREATE TABLE `transactions` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `purchase_date` datetime DEFAULT NULL,
  PRIMAR         


        

Answer 1

when you want to work with mysql using a function like this:

function insert($table, $info_array){
    // implode keys as columns by [`,`] glue string
    $columns = implode("`,`", array_keys($info_array));

    // implode values as sql ready values by [','] glue string
    $values = implode("','", array_values($info_array));

    // make query(careful about [`] for columns name and ['] for values)
    $sql = "INSERT INTO ".$table." (`".$columns."`) VALUES ('".$values."');";
    return $sql;
}

you should be careful about [ ` ] for table columns names and [ ' ] or [ " ] for values. for example, I used above function this way:

try{
        $db_insert_sample_user = $connection->query(insert(TABLE_PREFIX."users", [
            "username" => "my_name_2",
            "password" => md5("how457fty")
        ]));
        echo '
';
        print_r($db_insert_sample_user);
        echo '
';
    }catch (PDOException $exc){
        echo '
';
        print_r($exc);
        echo '
';
    }

the query string is this:

INSERT INTO php_pdo_users (`username`,`password`) VALUES ('my_name_2','ee04708d313adf4ff8ba321acf3eb568');

and the result was like : (for two users) PHPMyAdmin Result

if you want functions based on prepared statements, test this : (placeholders, params and values, don't need [ ' ] or [ " ] at all!!!)

function insert_prepared(PDO $connection, $table, $info_array){
    // columns
    $columns = implode("`,`", array_keys($info_array));

    // placeholders
    $place_holders = [];
    for ( $i = 0; count(array_keys($info_array)) > $i; $i++){
        $place_holders[] = '?';
    }

    // convert placeholders to query string
    $place_holders_str = implode(",", $place_holders);
    $prepared_stmt = "INSERT INTO ".$table." (`".$columns."`) VALUES (".$place_holders_str.");";

    // prepare statement
    $stmt = $connection->prepare($prepared_stmt);

    // values
    $values = array_values($info_array);

    // bind all params to values
    for($i = 0; count($values) > $i; $i++){
        $stmt->bindParam($i + 1, $values[$i]);
    }

    // execute and return results
    return $stmt->execute();
}

after code execution this way :

try {
        $db_insert_sample_user = insert_prepared(
            $connection,
            TABLE_PREFIX . "users",
            [
                "username" => "my_name_4",
                "password" => md5( "HelloDolly#__3" )
            ]
        );
    } catch ( PDOException $exc ) {
        echo "Failed : " . $exc->getMessage();
    }

results is : Results with insert_prepared function