Question

我有一个数据库，其中有一行称为形状，包含带有矩形，正方形和圆形的条目。我目前有以下代码，只获得用户请求的形状。（目前它是矩形和圆形，正方形和圆形或仅圆形）。由于某种原因，它不起作用并抛出数据库错误。谁能帮我？ “MEMBER_FROM”是他们所在的专栏

$where = "";
    if($context['no_sq'] == 1 && $context['no_rec'] == 0) {
        $where .= " WHERE MEMBER_FROM != 'Square'";
    } else if($context['no_sq'] == 1 && $context['no_rec'] == 0) {
        $where .= " WHERE MEMBER_FROM != 'Rectangle'";
    } else if($context['no_sq'] == 1 && $context['no_rec'] == 1) {
        $where .= " WHERE MEMBER_FROM != 'Square' AND MEMBER_FROM != 'Rectangle'";
    }
    $request = mysql_query("SELECT ID_SHAPES FROM {$db_prefix}shapes WHERE ID_MEMBER = {$memID}{$where}", __FILE__, __LINE__);

Answer 1

你不能说WHERE两次。使用AND ...

   $where = "";
        if($context['no_squ'] == 1 && $context['no_rec'] == 0) {
            $where .= " AND MEMBER_FROM != 'Square'";
        } else if($context['no_sq'] == 1 && $context['no_rec'] == 0) {
            $where .= " AND MEMBER_FROM != 'Rectangle'";
        } else if($context['no_sq'] == 1 && $context['no_rec'] == 1) {
            $where .= " AND MEMBER_FROM != 'Square' AND MEMBER_FROM != 'Rectangle'";
        } 

     $request = mysql_query("SELECT ID_SHAPES FROM {$db_prefix}shapes WHERE ID_MEMBER = {$memID}{$where}", __FILE__, __LINE__);

<强>更新根据您的声明，您的形状是排除复选框，在数组中命名这些框然后基于循环构建您的查询会更有意义。否则这段代码可能很难维护......

<input type="checkbox" name="exclude[]" value="Square"> Square
<input type="checkbox" name="exclude[]" value="Rectangle"> Rectangle
<input type="checkbox" name="exclude[]" value="Circle"> Circle

然后在PHP中

foreach($_POST['exclude'] AS $exclude)
{
    $where .= " AND MEMBER_FROM != '".$exclude."'";
}

...显然逃避了$ exclude var，但为了简单起见，我们假设您正在逃避用户输入。

Answer 2

您在查询中添加了多个WHERE子句，这是非法的。此外，在这种情况下，您可能更喜欢NOT IN的语法。请注意，我也冒昧地清理了你的逻辑结构。

$sql = "SELECT ID_SHAPES FROM {$db_prefix}shapes WHERE ID_MEMBER = {$memID}";
$disallowed = array();
if($context['no_squ']) $disallowed[] = 'Square';
if($context['no_rec']) $disallowed[] = 'Rectangle';
if(count($disallowed)) {
    $sql .= 'AND MEMBER_FROM NOT IN ("' . implode('", "', $disallowed) . '")';
}
$request = mysql_query($sql);

MySQL：根据值排除列

2 个答案: