Question

我在下面的代码段中，从下拉列表用户选择中提取$filter_xx值。

我正在尝试使用用户选择通过下拉列表选择查询数据库来查询mySQL数据库。

您将看到有4个$filter_xx变量，并且在给定实例中设置了多少变量是完全随机的。

问题是当我在查询中使用&&时，它检查所有四个参数是否为真，然后抛出并输出。（我知道&&假设以这种方式工作！）。我尝试用&&替换所有||运算符，但没有运气。

如何仅使用用户选择的选项搜索数据库？

    if(isset($filter_brand) || isset($filter_year) || isset($filter_month) || isset($filter_status)) 
         {
          $query = "SELECT * FROM targets WHERE brand='$filter_brand' && startyear='$filter_year' && startmonth='$filter_month' && status='$filter_status' ORDER BY createdon DESC";
          } else {
          $query = "SELECT * FROM targets ORDER BY createdon DESC";
         }

Answer 1

如果有多个值必须以类似方式工作，请将数组与循环一起使用。我想，你正在使用mysqli，如果需要，可以更改PDO的引用。

$mysqli = new mysqli("localhost", "user", "pass", "test");
//...

//SQL attr name => name of POST parameter
$filter = array('brand' => 'brand', 'startyear' => 'year', 
                'startmonth' => 'month', 'status' => 'status');

//here we'll store SQL conditions
$sql_filter = array();

foreach($filter as $key => $value)
{
    if (isset($_POST[$value]))
    {
        //use your library function to quote the variable before using it in SQL
        $sql_filter[] = $key . '="'. $mysqli->escape_string($_POST[$value]) . '"';
    }
}

$query = "SELECT * FROM targets ";

if(isset($sql_filter[0]))
{
    $query .= 'WHERE ' . implode(' AND ', $sql_filter) . ' ';
}

$query .= 'ORDER BY createdon DESC';

Answer 2

试试这个

$join = "";
//TAKE ONE BLANK VARIBLE THAT JOIN IF VALUE IS SET

if(isset($filter_brand)){
    //IF VALUE ISSET THAN IT ADDED TO QUERY 
    $join .= " AND brand='$filter_brand'";
}

if(isset($filter_year){
    $join .= " AND startyear='$filter_year'";
}

$query = "SELECT * FROM targets WHERE id != '' $join ORDER BY createdon DESC";

Answer 3

试试这个：

$query = "SELECT * FROM targets WHERE 1 ";
$query = isset($filter_brand) ? $query . " AND brand = '".$filter_brand."'" : $query;
$query = isset($filter_year) ? $query . " AND startyear = '".$filter_year."'" : $query;
$query = isset($filter_month) ? $query . " AND startmonth = '".$filter_month."'" : $query;
$query = isset($filter_status) ? $query . " AND status = '".$filter_status."'" : $query;
$query .= " ORDER BY createdon DESC";

Answer 4

您可以这样做：

ᴀᴀ ʙᴄ ᴅᴀ

使用下拉值查询mySQL数据库

4 个答案: