构建自己的PHP框架--实现Model类3

先来看findAll方法，这个方法和findOne很相似。

publicstaticfunction findOne($condition = null)
    {
        $sql = 'select * from ' . static::tableName();$params = [];// 判空if(!empty($condition)) {
            $sql .= ' where ';$params = array_values($condition);$keys = [];foreach($conditionas$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 = $stmt->fetchAll(PDO::FETCH_ASSOC);foreach($rowsas$row) {
                if(!empty($row)) {
                    $model = newstatic();foreach($rowas$rowKey => $rowValue) {
                        $model->$rowKey = $rowValue;
                    }
                    array_push($models,$model);
                }
            }
        }

        returnnull;
    }

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     * @parammixed $condition a set of column values     * @return string     */publicstaticfunction buildWhere($condition,$params = null)
    {
        if(is_null($params)) {
            $params = [];
        }

        $where = '';if(!empty($condition)) {
            $where .= ' where ';$keys = [];foreach($conditionas$key => $value) {
                array_push($keys,"$key = ?");array_push($params,$value);
            }
            $where .= implode(' and ',$keys);
        }
        return[$where,$params];
    }

    /**     * Convert array to model     * @parammixed $row the row data from database     */publicstaticfunction arr2Model($row)
    {
        $model = newstatic();foreach($rowas$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]);     * ```     *     * @parammixed $condition a set of column values     * @return static|null Model instance matching the condition, or null if nothing matches.     */publicstaticfunction findOne($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)) {
                returnstatic::arr2Model($row);
            }
        }

        returnnull;
    }

    /**     * 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]);     * ```     *     * @parammixed $condition a set of column values     * @return array an array of Model instance, or an empty array if nothing matches.     */publicstaticfunction findAll($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 = $stmt->fetchAll(PDO::FETCH_ASSOC);foreach($rowsas$row) {
                if(!empty($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']);     * ~~~     *     * @paramarray $attributes attribute values (name-value pairs) to be saved for the model.     * @paramarray $condition the condition that matches the models that should get updated.     * An empty condition will match all models.     * @return integer the number of rows updated     */publicstaticfunction updateAll($condition,$attributes)
    {
        $sql = 'update ' . static::tableName();$params = [];if(!empty($attributes)) {
            $sql .= ' set ';$params = array_values($attributes);$keys = [];foreach($attributesas$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]);     * ~~~     *     * @paramarray $condition the condition that matches the models that should get deleted.     * An empty condition will match all models.     * @return integer the number of rows deleted     */publicstaticfunction deleteAll($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.     */publicfunction insert()
    {
        $sql = 'insert into ' . static::tableName();$params = [];$keys = [];foreach($thisas$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$primaryKeys = static::primaryKey();foreach($primaryKeysas$name) {
            // Get the primary key$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.     */publicfunction update()
    {
        $primaryKeys = static::primaryKey();$condition = [];foreach($primaryKeysas$name) {
            $condition[$name] = isset($this->$name)?$this->$name:null;
        }

        $attributes = [];foreach($thisas$key => $value) {
            if(!in_array($key,$primaryKeys,true)) {
                $attributes[$key] = $value;
            }
        }

        returnstatic::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.     */publicfunction delete()
    {
        $primaryKeys = static::primaryKey();$condition = [];foreach($primaryKeysas$name) {
            $condition[$name] = isset($this->$name)?$this->$name:null;
        }

        returnstatic::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

以上就介绍了构建自己的PHP框架--实现Model类3，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。