这些功能是否检查到数据库的连接并显示数据？

Question

有人可以解释这两个功能的作用吗？我认为他们会检查您是否连接到数据库，如果未显示错误，但我不确定。我也不知道是怎么回事。有人可以解释一下吗？<?php    private function getData($sqlQuery) {  $result = mysqli_query($this->dbConnect, $sqlQuery);  if(!$result){    die('Error in query: '. mysqli_error());  } //peforms a  query against database to check it is connected  $data= array();  while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {    $data[]=$row;  }  return $data;}private function getNumRows($sqlQuery) {    $result = mysqli_query($this->dbConnect, $sqlQuery);    if(!$result){        die('Error in query: '. mysqli_error());    }    $numRows = mysqli_num_rows($result);    return $numRows;}}?>

Answer 1

<?php    

private function getData($sqlQuery) {    //creates a function named 'getData' with a required parameter

  $result = mysqli_query($this->dbConnect, $sqlQuery); //uses mysqli to query against the "$dbConnect" resource using the passed parameter $sqlQuery

  if(!$result){ //If the result doesn't exist die

    die('Error in query: '. mysqli_error());//die and show error

  } //peforms a  query against database to check it is connected

  $data= array();//create an empty array

  while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {//fetch a row using association (aka an array mapped by keys with no numbered index)

    $data[]=$row;//array push the returned row

  } 

 return $data;//return an array of arrays that you've gotten from MySqlI

}

private function getNumRows($sqlQuery) {//create a function

    $result = mysqli_query($this->dbConnect, $sqlQuery);//query

    if(!$result){//if no result die

        die('Error in query: '. mysqli_error());//die and show error

    }

    $numRows = mysqli_num_rows($result);//get the number of rows in the query

    return $numRows;//return the number of rows in the query

}

}

?>

希望这可以帮助