摘要：使用創建測試庫和表代碼測試運行結果工具類安裝框架中使用建議在框架中使用類用單例模式或者用依賴容器來管理較好。

create database db_test;
CREATE TABLE `user` (
    `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
    `name` char(11) NOT NULL,
    `created_at` int(10) unsigned NOT NULL,
    PRIMARY KEY (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `user` VALUES ("1", "wang", "1501109027");
INSERT INTO `user` VALUES ("2", "meng", "1501109026");
INSERT INTO `user` VALUES ("3", "liu", "1501009027");
INSERT INTO `user` VALUES ("4", "yuan", "1500109027");

require __DIR__ . "/DB.php";
$db = new DB();
$db->__setup([
    "dsn"=>"mysql:dbname=db_test;host=localhost",
    "username"=>"root",
    "password"=>"******",
    "charset"=>"utf8"
]);


$user = $db->fetch("SELECT * FROM user where id = :id", ["id" => 1]);
echo $user["name"];
echo "
";

$insertId = $db->insert("user", ["name" => "salamander", "created_at" => time()]);
echo "insert user {$insertId}
";
$users = $db->fetchAll("SELECT * FROM user");
foreach ($users as $item) {
    echo "user {$item["id"]} is {$item["name"]} 
";
}   

運行結果

dsn = $config["dsn"];
        $this->user = $config["username"];
        $this->password = $config["password"];
        $this->charset = $config["charset"];
        $this->connect();
    }

    private function connect()
    {
        if(!$this->dbh){
            $options = array(
                PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES " . $this->charset,
            );
            $this->dbh = new PDO($this->dsn, $this->user,
                $this->password, $options);
        }
    }

    public function beginTransaction()
    {
        return $this->dbh->beginTransaction();
    }

    public function inTransaction()
    {
        return $this->dbh->inTransaction();
    }

    public function rollBack()
    {
        return $this->dbh->rollBack();
    }

    public function commit()
    {
        return $this->dbh->commit();
    }

    function watchException($execute_state)
    {
        if(!$execute_state){
            throw new MySQLException("SQL: {$this->lastSQL}
".$this->sth->errorInfo()[2], intval($this->sth->errorCode()));
        }
    }

    public function fetchAll($sql, $parameters=[])
    {
        $result = [];
        $this->lastSQL = $sql;
        $this->sth = $this->dbh->prepare($sql);
        $this->watchException($this->sth->execute($parameters));
        while($result[] = $this->sth->fetch(PDO::FETCH_ASSOC)){ }
        array_pop($result);
        return $result;
    }

    public function fetchColumnAll($sql, $parameters=[], $position=0)
    {
        $result = [];
        $this->lastSQL = $sql;
        $this->sth = $this->dbh->prepare($sql);
        $this->watchException($this->sth->execute($parameters));
        while($result[] = $this->sth->fetch(PDO::FETCH_COLUMN, $position)){ }
        array_pop($result);
        return $result;
    }

    public function exists($sql, $parameters=[])
    {
        $this->lastSQL = $sql;
        $data = $this->fetch($sql, $parameters);
        return !empty($data);
    }

    public function query($sql, $parameters=[])
    {
        $this->lastSQL = $sql;
        $this->sth = $this->dbh->prepare($sql);
        $this->watchException($this->sth->execute($parameters));
        return $this->sth->rowCount();
    }

    public function fetch($sql, $parameters=[], $type=PDO::FETCH_ASSOC)
    {
        $this->lastSQL = $sql;
        $this->sth = $this->dbh->prepare($sql);
        $this->watchException($this->sth->execute($parameters));
        return $this->sth->fetch($type);
    }

    public function fetchColumn($sql, $parameters=[], $position=0)
    {
        $this->lastSQL = $sql;
        $this->sth = $this->dbh->prepare($sql);
        $this->watchException($this->sth->execute($parameters));
        return $this->sth->fetch(PDO::FETCH_COLUMN, $position);
    }

    public function update($table, $parameters=[], $condition=[])
    {
        $table = $this->format_table_name($table);
        $sql = "UPDATE $table SET ";
        $fields = [];
        $pdo_parameters = [];
        foreach ( $parameters as $field=>$value){
            $fields[] = "`".$field."`=:field_".$field;
            $pdo_parameters["field_".$field] = $value;
        }
        $sql .= implode(",", $fields);
        $fields = [];
        $where = "";
        if(is_string($condition)) {
            $where = $condition;
        } else if(is_array($condition)) {
            foreach($condition as $field=>$value){
                $parameters[$field] = $value;
                $fields[] = "`".$field."`=:condition_".$field;
                $pdo_parameters["condition_".$field] = $value;
            }
            $where = implode(" AND ", $fields);
        }
        if(!empty($where)) {
            $sql .= " WHERE ".$where;
        }
        return $this->query($sql, $pdo_parameters);
    }

    public function insert($table, $parameters=[])
    {
        $table = $this->format_table_name($table);
        $sql = "INSERT INTO $table";
        $fields = [];
        $placeholder = [];
        foreach ( $parameters as $field=>$value){
            $placeholder[] = ":".$field;
            $fields[] = "`".$field."`";
        }
        $sql .= "(".implode(",", $fields).") VALUES (".implode(",", $placeholder).")";

        $this->lastSQL = $sql;
        $this->sth = $this->dbh->prepare($sql);
        $this->watchException($this->sth->execute($parameters));
        $id = $this->dbh->lastInsertId();
        if(empty($id)) {
            return $this->sth->rowCount();
        } else {
            return $id;
        }
    }

    public function errorInfo()
    {
        return $this->sth->errorInfo();
    }

    protected function format_table_name($table)
    {
        $parts = explode(".", $table, 2);

        if(count($parts) > 1) {
            $table = $parts[0].".`{$parts[1]}`";
        } else {
            $table = "`$table`";
        }
        return $table;
    }

    function errorCode()
    {
        return $this->sth->errorCode();
    }
}

class MySQLException extends Exception { }

SimpleDB

在框架中使用DB類,用單例模式或者用依賴容器來管理較好。