Question

我正在构建这个简单的html表单，用于向/从mysql数据库插入/检索数据。刚启动时有两个按钮：查找和重置。它们都工作正常但是当我点击FIND而字段为空时会出现这些错误：

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in V:\u\miramo\Forum\xampp\htdocs\miramo_licensedb\myclass.php on line 76

Warning: mysql_free_result() expects parameter 1 to be resource, boolean given in V:\u\miramo\Forum\xampp\htdocs\miramo_licensedb\myclass.php on line 81

这是myclass.php件：

    public function find() {

    $this->queryString = $this->makeQueryString();
    $this->errorMessages=$this->queryString;
    $query = mysql_query ($this->queryString);

    while($row=mysql_fetch_array($query)):
        $this->id= $row['id'];
        $this->name= $row['name'];
        $this->email = $row['email'];           
    endwhile; 
    mysql_free_result($query);

和myform.php：

 <?php
 include_once("./myclass.php");
 $my_class = new MyClass;


?>
<form action="myform.php" method="post">

<input type="text" value="<?php echo $my_class->id; ?>" name="id" class="" />
<input type="text" value="<?php echo $my_class->name; ?>" name="name" class="" />
<input type="text" value="<?php echo $my_class->email; ?>" name="email" class="" />


 <input type="submit" name="find" value="Find" />
 <input type="submit" name="reset" value="reset" />


  </form>

我尝试通过添加

来解决这个问题

  if($result === FALSE){
  die(mysql_error());
  }

在我的while循环之前

但它没有帮助。希望如果在空字段上运行查询，将显示消息“插入值”。有什么建议？？？高度赞赏

那就是查询：

    public function makeQueryString(){
    // build array of search terms
    $res= "SELECT id, name, email FROM test1 ";

// build array of search terms
 $i=0;


 if ($_POST['id'])
     $searchTermsArray[$i++] = "id LIKE '{$_POST['id']}'";
 if ($_POST['name'])
   $searchTermsArray[$i++] = "name LIKE '{$_POST['name']}'";
 if ($_POST['email'])
   $searchTermsArray[$i++] = "email LIKE '{$_POST['email']}'";

    // Construct query string from search terms array
 if ($i > 0 ) {
    $j=0;   
    $res .= " WHERE " . $searchTermsArray[0];

    for ($j=1; $j < $i; $j++)
        $res = $res . " AND " . $searchTermsArray[$j];
}
else
    $res= "";

 //Return query string
 return($res);
 }

Answer 1

问题是您正在尝试执行空查询。在执行生成的查询（可能为空）之前检查这种情况;

public function find() {

$this->queryString = $this->makeQueryString();

if(empty($this->queryString))
{
    echo "Insert values";
    return;
}
else
{
    $this->errorMessages=$this->queryString;
    $query = mysql_query ($this->queryString);

    while($row=mysql_fetch_array($query)):
        $this->id= $row['id'];
        $this->name= $row['name'];
        $this->email = $row['email'];           
    endwhile; 
    mysql_free_result($query);
}

在空字段上运行查询时出错

1 个答案: