在之前的博客中，我们实现并完善了model类的findone方法，下面我们来实现其中的其他方法。
先来看findall方法，这个方法和findone很相似。
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; }
你会发现有findone和findall方法很相似，明显可以将公共的部分抽出来，然后我们就多了如下两个方法：
/** * 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; }
分别是构建sql中where部分的方法和将查找到的array转换成model的方法。大家会奇怪第一个方法中为什么需要params参数和返回值，其实这个为了之后的updateall方法的使用。其实这个地方跟适合使用引用传值。
这样我们的findone和findall就便成了如下内容：
/** * 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; }
剩下的updateall/deleteall/insert/update和delete方法就不一一详细说明了，直接给出代码。其基本思想都是一致的，都是按照规则拼接sql语句。
/** * 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; }
这样基本的model就算是暂时完成了，虽然可能还有很多问题和局限，但暂时先这样了，我们之后有机会会一步一步的去完善。
好了，今天就先到这里。项目内容和博客内容也都会放到github上，欢迎大家提建议。
code：https://github.com/craryprimitiveman/simple-framework/tree/0.7
blog project：https://github.com/craryprimitiveman/create-your-own-php-framework