独自の PHP フレームワークを構築して Model クラスを実装する (3)

前回のブログでは、Model クラスの findOne メソッドを実装して改良しました。その中に他のメソッドも実装してみましょう。

まず findAll メソッドを見てみましょう。このメソッドは findOne とよく似ています。

    public static function findOne($condition = null)    {        $sql = 'select * from ' . static::tableName();        $params = [];        // 判空        if (!empty($condition)) {            $sql .= ' where ';            $params = array_values($condition);            $keys = [];            foreach ($condition as $key => $value) {                array_push($keys, "$key = ?");            }            $sql .= implode(' and ', $keys);        }        $stmt = static::getDb()->prepare($sql);        $rs = $stmt->execute($params);        $models = [];        if ($rs) {            // 直接获取出所有符合条件的            $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);            foreach ($rows as $row) {                if (!empty($row)) {                    $model = new static();                    foreach ($row as $rowKey => $rowValue) {                        $model->$rowKey = $rowValue;                    }                    array_push($models, $model);                }            }        }        return null;    }

findOne メソッドと findAll メソッドが非常に似ていることがわかります。共通部分を抽出できることは明らかであり、さらに次の 2 つのメソッドがあります。

    /** * Build a sql where part * @param mixed $condition a set of column values * @return string */    public static function buildWhere($condition, $params = null)    {        if (is_null($params)) {            $params = [];        }        $where = '';        if (!empty($condition)) {            $where .= ' where ';            $keys = [];            foreach ($condition as $key => $value) {                array_push($keys, "$key = ?");                array_push($params, $value);            }            $where .= implode(' and ', $keys);        }        return [$where, $params];    }    /** * Convert array to model * @param mixed $row the row data from database */    public static function arr2Model($row)    {        $model = new static();        foreach ($row as $rowKey => $rowValue) {            $model->$rowKey = $rowValue;        }        return $model;    }

は、 のメソッドとメソッドです。 SQL の where 部分をそれぞれ構築して、見つかった配列をモデルに変換します。なぜ最初のメソッドで params パラメータと戻り値が必要なのか疑問に思われるかもしれませんが、これは後で updateAll メソッドを使用するためです。実際、これは参照渡しが適している場所です。

このようにして、findOne と findAll は次のようになります:

    /** * Returns a single model instance by a primary key or an array of column values. * * ```php * // find the first customer whose age is 30 and whose status is 1 * $customer = Customer::findOne(['age' => 30, 'status' => 1]); * ``` * * @param mixed $condition a set of column values * @return static|null Model instance matching the condition, or null if nothing matches. */    public static function findOne($condition = null)    {        list($where, $params) = static::buildWhere($condition);        $sql = 'select * from ' . static::tableName() . $where;        $stmt = static::getDb()->prepare($sql);        $rs = $stmt->execute($params);        if ($rs) {            $row = $stmt->fetch(PDO::FETCH_ASSOC);            if (!empty($row)) {                return static::arr2Model($row);            }        }        return null;    }    /** * Returns a list of models that match the specified primary key value(s) or a set of column values. * * ```php * // find customers whose age is 30 and whose status is 1 * $customers = Customer::findAll(['age' => 30, 'status' => 1]); * ``` * * @param mixed $condition a set of column values * @return array an array of Model instance, or an empty array if nothing matches. */    public static function findAll($condition = null)    {        list($where, $params) = static::buildWhere($condition);        $sql = 'select * from ' . static::tableName() . $where;        $stmt = static::getDb()->prepare($sql);        $rs = $stmt->execute($params);        $models = [];        if ($rs) {            $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);            foreach ($rows as $row) {                if (!empty($row)) {                    $model = static::arr2Model($row);                    array_push($models, $model);                }            }        }        return $models;    }

残りの updateAll/deleteAll/insert/update および delete メソッドについては、1 つずつ詳しく説明せず、コードを直接示します。基本的な考え方は同じで、すべてルールに従って SQL ステートメントを結合します。

    /** * Updates models using the provided attribute values and conditions. * For example, to change the status to be 2 for all customers whose status is 1: * * ~~~ * Customer::updateAll(['status' => 1], ['status' => '2']); * ~~~ * * @param array $attributes attribute values (name-value pairs) to be saved for the model. * @param array $condition the condition that matches the models that should get updated. * An empty condition will match all models. * @return integer the number of rows updated */    public static function updateAll($condition, $attributes)    {        $sql = 'update ' . static::tableName();        $params = [];        if (!empty($attributes)) {            $sql .= ' set ';            $params = array_values($attributes);            $keys = [];            foreach ($attributes as $key => $value) {                array_push($keys, "$key = ?");            }            $sql .= implode(' , ', $keys);        }        list($where, $params) = static::buildWhere($condition, $params);        $sql .= $where;        $stmt = static::getDb()->prepare($sql);        $execResult = $stmt->execute($params);        if ($execResult) {            // 获取更新的行数            $execResult = $stmt->rowCount();        }        return $execResult;    }    /** * Deletes models using the provided conditions. * WARNING: If you do not specify any condition, this method will delete ALL rows in the table. * * For example, to delete all customers whose status is 3: * * ~~~ * Customer::deleteAll([status = 3]); * ~~~ * * @param array $condition the condition that matches the models that should get deleted. * An empty condition will match all models. * @return integer the number of rows deleted */    public static function deleteAll($condition)    {        list($where, $params) = static::buildWhere($condition);        $sql = 'delete from ' . static::tableName() . $where;        $stmt = static::getDb()->prepare($sql);        $execResult = $stmt->execute($params);        if ($execResult) {            // 获取删除的行数            $execResult = $stmt->rowCount();        }        return $execResult;    }    /** * Inserts the model into the database using the attribute values of this record. * * Usage example: * * ```php * $customer = new Customer; * $customer->name = $name; * $customer->email = $email; * $customer->insert(); * ``` * * @return boolean whether the model is inserted successfully. */    public function insert()    {        $sql = 'insert into ' . static::tableName();        $params = [];        $keys = [];        foreach ($this as $key => $value) {            array_push($keys, $key);            array_push($params, $value);        }        // 构建由？组成的数组，其个数与参数相等数相同        $holders = array_fill(0, count($keys), '?');        $sql .= ' (' . implode(' , ', $keys) . ') values ( ' . implode(' , ', $holders) . ')';        $stmt = static::getDb()->prepare($sql);        $execResult = $stmt->execute($params);        // 将一些自增值赋回Model中        $primaryKeys = static::primaryKey();        foreach ($primaryKeys as $name) {            // Get the primary key            $lastId = static::getDb()->lastInsertId($name);            $this->$name = (int) $lastId;        }        return $execResult;    }    /** * Saves the changes to this model into the database. * * Usage example: * * ```php * $customer = Customer::findOne(['id' => $id]); * $customer->name = $name; * $customer->email = $email; * $customer->update(); * ``` * * @return integer|boolean the number of rows affected. * Note that it is possible that the number of rows affected is 0, even though the * update execution is successful. */    public function update()    {        $primaryKeys = static::primaryKey();        $condition = [];        foreach ($primaryKeys as $name) {            $condition[$name] = isset($this->$name) ? $this->$name : null;        }        $attributes = [];        foreach ($this as $key => $value) {            if (!in_array($key, $primaryKeys, true)) {                $attributes[$key] = $value;            }        }        return static::updateAll($condition, $attributes) !== false;    }    /** * Deletes the model from the database. * * @return integer|boolean the number of rows deleted. * Note that it is possible that the number of rows deleted is 0, even though the deletion execution is successful. */    public function delete()    {        $primaryKeys = static::primaryKey();        $condition = [];        foreach ($primaryKeys as $name) {            $condition[$name] = isset($this->$name) ? $this->$name : null;        }        return static::deleteAll($condition) !== false;    }

この基本的なモデルはまだ多くの問題や制限があるかもしれませんが、現時点ではこれだけです。機会があれば段階的に改善していきます。

さて、今日はここまでにしましょう。プロジェクトの内容やブログの内容も Github に載せる予定ですので、皆様からのご提案をお待ちしております。

コード: https://github.com/CraryPrimitiveMan/simple-framework/tree/0.7

ブログプロジェクト: https://github.com/CraryPrimitiveMan/create-your-own-php-framework