我有一个用户界面，用户可以在其中键入一个人的名字和姓氏。只要我在搜索框中不输入任何内容，就不会找到任何用户。但是只要我输入一个空格，就会返回数据库中的每个用户。我修剪输入字符串并检查空白:
if (isset($_GET['lastname'])) {
$lastname_value = trim($_GET['lastname']);
//This Line is only used for setting the Text again in the Search Box
$tpl->setVariable('ss-search-lastname-value', $lastname_value);
}
if(isset($_GET['firstname'])) {
$firstname_value = trim($_GET['firstname']);
$tpl->setVariable('ss-search-firstname-value',$firstname_value);
}
之后，我编写搜索查询:
$sql = "SELECT e.`user_id`, e.`firstname`, e.`lastname`, e.`email`
FROM `employees` as e
WHERE 1";
if($lastname_value!="") {
$sql .=" AND e.`lastname` ='$lastname_value'";
}
if($firstname_value!="") {
$sql .=" AND e.`firstname` ='$firstname_value'";
}
一个正常的搜索返回期望的用户和正确的名字和姓氏，如果我什么都不输入并开始搜索，则不返回任何结果。然而，在搜索框中的一个空白，我得到了所有的用户。我怎样才能解决这个问题呢?
您需要首先决定是否要搜索:
$doSearch = false;
$hasLastname = $lastname_value != "";
$hasFirstname = $firstname_value != "";
$doSearch = $hasLastname || $hasFirstname;
if ($doSearch)
{
$sql = "SELECT e.`user_id`, e.`firstname`, e.`lastname`, e.`email`
FROM `employees` as e
WHERE 1";
if($lastname_value!="") {
$sql .=" AND e.`lastname` ='$lastname_value'";
}
if($firstname_value!="") {
$sql .=" AND e.`lastname` ='$firstname_value'";
}
...
}