php - 这些函数是否检查是否有与数据库的连接并显示数据?
问题描述
有人能解释一下这两个函数的作用吗?我认为他们会检查您是否连接到数据库,如果没有显示错误,但我不完全确定。我也不知道逐行发生了什么。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 $numRows;
}
}
?>
解决方案
<?php
private function getData($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
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