php - Ajax 和 PHP : MySQL Query Not Fetching Any Rows

Question

我设置了 3 个组合框来过滤来自 MySQL 数据库的结果。加载时，所有结果都按正确顺序显示，但是当我尝试从 3 个组合框中选择任意 1 个，或从 3 个组合框中选择任意 2 个时，没有显示任何结果(行)。如果我选择所有 3 个组合框，则会显示结果。

我希望有人能找出我的查询代码有什么问题。我已经尝试了一切，似乎找不到任何问题。我也想知道我是否以最好的方式做这件事。我是 PHP 的新手，所以我不知道所有可用的不同方法。

PHP:

//Define Refine Data Values
$imgFamily = $_GET['imgFamily'];
$imgClass = $_GET['imgClass'];
$imgGender = $_GET['imgGender'];



//Define Refine Values as True of False
$imgFamilyTrue = (($imgFamily != 1) || ($imgFamily != null));
$imgFamilyFalse = (($imgFamily == 1) || ($imgFamily == null));

$imgClassTrue = (($imgClass != 1) || ($imgClass != null));
$imgClassFalse = (($imgClass == 1) || ($imgClass == null));

$imgGenderTrue = (($imgGender != 1) || ($imgGender != null));
$imgGenderFalse = (($imgGender == 1) || ($imgGender == null));



include"db.php";

//Database queries based on refine selections
if($imgFamilyFalse && $imgClassFalse && $imgGenderFalse) {
    $query_pag_data = "SELECT `imgURL`,`imgTitle` FROM `images` ".
    "ORDER BY `imgDate` DESC";

} else if($imgFamilyTrue && $imgClassTrue && $imgGenderTrue) {
    $query_pag_data = "SELECT `imgURL`,`imgTitle` FROM `images` WHERE imgFamily='$imgFamily' AND imgClass='$imgClass' AND imgGender='$imgGender' ".
    "ORDER BY `imgDate` DESC";

} else if($imgFamilyTrue && $imgClassFalse && $imgGenderFalse) {
    $query_pag_data = "SELECT `imgURL`,`imgTitle` FROM `images` WHERE imgFamily='$imgFamily' ".
    "ORDER BY `imgDate` DESC";

} else if($imgFamilyFalse && $imgClassTrue && $imgGenderFalse) {
    $query_pag_data = "SELECT `imgURL`,`imgTitle` FROM `images` WHERE imgClass='$imgClass' ".
    "ORDER BY `imgDate` DESC";

} else if($imgFamilyFalse && $imgClassFalse && $imgGenderTrue) {
    $query_pag_data = "SELECT `imgURL`,`imgTitle` FROM `images` WHERE imgGender='$imgGender' ".
    "ORDER BY `imgDate` DESC";

} else if($imgFamilyFalse && $imgClassTrue && $imgGenderTrue) {
    $query_pag_data = "SELECT `imgURL`,`imgTitle` FROM `images` WHERE imgClass='$imgClass' AND imgGender='$imgGender' ".
    "ORDER BY `imgDate` DESC";

} else if($imgFamilyTrue && $imgClassFalse && $imgGenderTrue) {
    $query_pag_data = "SELECT `imgURL`,`imgTitle` FROM `images` WHERE imgFamily='$imgFamily' AND imgGender='$imgGender' ".
    "ORDER BY `imgDate` DESC";

} else if($imgFamilyTrue && $imgClassTrue && $imgGenderFalse) {
    $query_pag_data = "SELECT `imgURL`,`imgTitle` FROM `images` WHERE imgFamily='$imgFamily' AND imgClass='$imgClass' ".
    "ORDER BY `imgDate` DESC";
}

我很确定问题出在 PHP 上，因为没有从 javascript 端调用错误，当我只有两个组合框时一切正常，但我会发布我的 jQuery Ajax 查询，以防出现问题就在那一端。

Ajax:

function loadData(imgFamily, imgClass, imgGender){
    $.ajax
    ({
        type: "GET",
        url: "filter_test.php",
        data: {imgFamily:imgFamily, imgClass:imgClass, imgGender:imgGender},
        success: function(msg) {
            $("#gallery_container").html(msg);
        },
        error: function(jqXHR, textStatus, errorThrown) {
        },
        complete: function() {
        }
    });
}

Answer 1

多么可怕的困惑。你绝对应该清理它:

$where_clauses = array();

$where_clauses[] = "1=1"; // default do-nothing clause

if ($_GET['imgFamily']) {
   $where_clauses[] = "imgFamily='$imgFamily'";
}
if ($_GET['imgClass']) {
   $where_clauses[] = "imgClass='$imgClass'";
}
if ($_GET['imgGender']) {
   $where_clauses[] = "imgFamily='$imgFamily'";
}

$clause = implode(' AND ', $where_clauses);
$sql = "SELECT imgURL, imgTitle FROM images WHERE $clause ORDER BY imgDate DESC";