为什么这不起作用？(Why doesn't this work? sqlit3 php)

 我想通过他的电子邮件地址或用户名获取用户...但它不起作用。 每次我使用字符串而不是数字，我只是得到假。 
 
 这是一个学校项目，所以我不能使用任何框架:( 
 
 这不起作用$ objAcc-> getUser（'email'，'example@gmail.com'） 
 
 这很有效 
 
$objAcc->getUser('user_id', '1')
 
 梅索德： 
 
    public function getUser($by = NULL, $value = NULL, $quantity = 0) {
        global $database;

        try {
            $row = array();
            if (isset($by) && isset($value)) {
                $query = 'SELECT * FROM "user" WHERE :by=:value';
                $stmt = $database->prepare($query);

                $type = ($by == 'user_id' || $by == 'phone' || $by == 'fax' || $by == 'zip' || $by == 'admin') ? SQLITE3_INTEGER : SQLITE3_TEXT;
                $stmt->bindValue(':by', $by, SQLITE3_TEXT);
                $stmt->bindValue(':value', $value, $type);

                $result = $stmt->execute();
            } else {
                $query = 'SELECT * FROM "user"';
                $stmt = $database->prepare($query);

                $result = $stmt->execute();
            }

            if ($quantity) {
                for ($i = 0; $i < $quantity; $i++) {
                    $row[ $i ] = $result->fetchArray(SQLITE3_ASSOC);
                }
            } else {
                $i = 0;
                while ($entry = $result->fetchArray(SQLITE3_ASSOC)) {
                    $row[ $i ] = $entry;
                    $i++;
                }
            }

            if (empty($row[0])) {
                return FALSE;
            }

            return $row;

        } catch (Exception $e) {
            var_dump($e);
            die();
        }
    }
 
 我希望你能帮助我们。 

I want to get the user by his email addresse or username ... but it doesn't work. Everytime i use a string and not a number, i just get false.
 
It's a school project so I can't use any frameworks :(
 
This doesn't work $objAcc->getUser('email', 'example@gmail.com')
 
This works
 
$objAcc->getUser('user_id', '1')
 
Methode:
 
    public function getUser($by = NULL, $value = NULL, $quantity = 0) {
        global $database;

        try {
            $row = array();
            if (isset($by) && isset($value)) {
                $query = 'SELECT * FROM "user" WHERE :by=:value';
                $stmt = $database->prepare($query);

                $type = ($by == 'user_id' || $by == 'phone' || $by == 'fax' || $by == 'zip' || $by == 'admin') ? SQLITE3_INTEGER : SQLITE3_TEXT;
                $stmt->bindValue(':by', $by, SQLITE3_TEXT);
                $stmt->bindValue(':value', $value, $type);

                $result = $stmt->execute();
            } else {
                $query = 'SELECT * FROM "user"';
                $stmt = $database->prepare($query);

                $result = $stmt->execute();
            }

            if ($quantity) {
                for ($i = 0; $i < $quantity; $i++) {
                    $row[ $i ] = $result->fetchArray(SQLITE3_ASSOC);
                }
            } else {
                $i = 0;
                while ($entry = $result->fetchArray(SQLITE3_ASSOC)) {
                    $row[ $i ] = $entry;
                    $i++;
                }
            }

            if (empty($row[0])) {
                return FALSE;
            }

            return $row;

        } catch (Exception $e) {
            var_dump($e);
            die();
        }
    }
 
I hope you can help me guys.

原文：https://stackoverflow.com/questions/34376398