สอบถามการเขียนแบบนี้มีผลเสียอะไรไหมครับ(connect/close database in class)

class test {
  private $sqlsrv = null;
  private $db_host;
  private $db_user;
  private $db_pass;
 function __construct() {
    $_conf = include('config.php');
    $this->db_host = $_conf['db']['host'];
    $this->db_user = $_conf['db']['user'];
    $this->db_pass = $_conf['db']['pass'];
 }
 private function connect_sql($database)
 {
   $conInfo = [
          'Database' => 'database',
          'UID' => $this->db_user,
          'PWD' => $this->db_pass,
          "CharacterSet"  => 'UTF-8',
          'MultipleActiveResultSets'=>true
   ];
   $this->sqlsrv = sqlsrv_connect($this->db_host,$conInfo)or die(print_r( sqlsrv_errors(), true));
 }
  private function db_close() {
      sqlsrv_close($this->sqlsrv);
  }
public function get_info($account)
 {
      $this->connect_sql();
      $result = 0;
      $sql = "EXEC select_info ?,?";
      $params = [
      [&$account,SQLSRV_PARAM_IN],
      [&$result,SQLSRV_PARAM_OUT]
      ];
      $stmt = sqlsrv_query($this->sqlsrv,$sql,$params);
      if( $stmt === false )die(print_r( sqlsrv_errors(), true));
      sqlsrv_free_stmt($stmt);
      $this->db_close();
      return $result;   
 }
public function get_info2($account)
 {
      $this->connect_sql();
      $result = 0;
      $sql = "EXEC select_info2 ?,?";
      $params = [
      [&$account,SQLSRV_PARAM_IN],
      [&$result,SQLSRV_PARAM_OUT]
      ];
      $stmt = sqlsrv_query($this->sqlsrv,$sql,$params);
      if( $stmt === false )die(print_r( sqlsrv_errors(), true));
      sqlsrv_free_stmt($stmt);
      $this->db_close();
      return $result;   
 }
public function get_info3($account)
 {
      $this->connect_sql();
      $result = 0;
      $sql = "EXEC select_info3 ?,?";
      $params = [
      [&$account,SQLSRV_PARAM_IN],
      [&$result,SQLSRV_PARAM_OUT]
      ];
      $stmt = sqlsrv_query($this->sqlsrv,$sql,$params);
      if( $stmt === false )die(print_r( sqlsrv_errors(), true));
      sqlsrv_free_stmt($stmt);
      $this->db_close();
      return $result;   
 }
}