Question

每次出现此错误时，都是database.php代码：

注意：未定义的变量：dbConn in   第15行的C：\ xampp \ htdocs \ couriermanagement \ database.php

警告：mysqli_query（）期望参数1为mysqli，null给定   在第15行的C：\ xampp \ htdocs \ couriermanagement \ database.php

警告：mysqli_error（）正好需要1个参数，给出0   第15行的C：\ xampp \ htdocs \ couriermanagement \ database.php

<?php


// database connection config
$dbHost = 'localhost';
$dbUser = 'root';
$dbPass = '';
$dbName = 'courier_db';

 $dbConn = mysqli_connect($dbHost, $dbUser, $dbPass, $dbName) or die ('MySQL 
 connect failed. ' . mysqli_error($dbConn));
//mysqli_select_db($dbConn ,$dbName) or die('Cannot select database. ' . 
  mysqli_error($dbConn));//

 function dbQuery($sql)
{
$result = mysqli_query($dbConn,$sql) or die(mysqli_error());

return $result;
}

function dbAffectedRows()
{
global $dbConn;

return mysqli_affected_rows($dbConn);
 }

 function dbFetchArray($result, $resultType = MYSQL_NUM) {
return mysqli_fetch_array($result, $resultType);
 }

 function dbFetchAssoc($result)
{
return mysqli_fetch_assoc($result);
}

 function dbFetchRow($result) 
{
return mysqli_fetch_row($result);
}

 function dbFreeResult($result)
 {
return mysqli_free_result($result);
 }

 function dbNumRows($result)
 {
return mysqli_num_rows($result);
 }

 function dbSelect($dbName)
 {
    return mysqli_select_db($dbName);
 }

 function dbInsertId()
  {
  return mysqli_insert_id();
  }
  ?>

Answer 1

缺少“链接”我认为你从mysql升级到mysqli

它应该是这样的：

$dbConn = mysqli_connect("localhost", "my_user", "my_password", "world");
mysqli_query($dbConn, "SELECT * FROM test");

读：

http://php.net/manual/en/mysqli.query.php

程序风格下的

Answer 2

您应该添加

$con=mysqli_connect("hostmane","userename","password","db_name");

在行之前

$result = mysqli_query($dbConn,$sql) or die(mysqli_error());

警告：mysqli_query（）需要至少2个参数，1在第15行的C：\ xampp \ htdocs \ couriermanagement \ database.php中给出

2 个答案: