我在PHP中有一个循环遍历一组名称(和相应数量)的数组。我想打印在MYSQL数据库表中找到的那些(我已成功连接到它)。我目前正在使用代码:
foreach ($arr as $name => $quan) {
$query = "SELECT * FROM table WHERE name='$name'";
$result = mysql_query($query) or die(mysql_error());
if (mysql_num_rows($result) > 0) {
$row = mysql_fetch_array($result);
echo $quan." ".$row['name']. "\n";
}
}
由于某种原因,这只会打印数组中的最后一个数量和名称。救命? 例如,如果数组具有{A-4,B-2,C-3}的键值对,并且表包含{A,B,D}作为名称......它将仅打印“2 B”
答案 0 :(得分:4)
将代码更改为以下内容:
foreach ($arr as $name => $quan) {
$query = "SELECT * FROM table WHERE name='$name'";
$result = mysql_query($query) or die(mysql_error());
if (mysql_num_rows($result) > 0) {
while($row = mysql_fetch_array($result)) {
echo $quan." ".$row['name']. "\n";
}
}
}
你必须遍历结果。顺便说一句,停止使用mysql_query()
!使用MySQLi或PDO(并注意 SQL注入;您可以使用mysqli_real_escape_string()
来处理输入参数)。对于MySQLi实现,这里是:
foreach ($arr as $name => $quan) {
$query = "SELECT * FROM table WHERE name='$name'";
$result = mysqli_query($query) or die(mysqli_error());
if (mysqli_num_rows($result) > 0) {
while($row = mysqli_fetch_array($result)) {
echo $quan." ".$row['name']. PHP_EOL;
}
}
}
而是"\n"
,我更喜欢使用PHP_EOL
(如上所示)
正如评论所暗示的那样,SQL语句可以执行一次,如下所示:
$flipped_array = array_flip($arr); // flip the array to make "name" as values"
for($i = 0; $i < count($flipped_array); $i++) {
$flipped_array[$i] = '\'' . $flipped_array[$i] . '\''; // add surrounding single quotes
}
$name_list = implode(',', $arr);
$query = "SELECT * FROM table WHERE name IN ($name_list)";
// ... omit the followings
e.g。在$ arr中包含“peter”,“mary”,“ken”,查询将是:
SELECT * FROM table WHERE name IN ('peter','mary','ken')
旁注:但我不明白您的查询。您只从查询中获取名称?您可以检查行数,或者甚至可以按名称分组,例如:
SELECT name, COUNT(*) AS cnt FROM table GROUP BY name ORDER BY name
得到你想要的东西。
更新(再次):根据OP的评论,以下是解决方案:
$flipped_array = array_flip($arr); // flip the array to make "name" as values"
for($i = 0; $i < count($flipped_array); $i++) {
$flipped_array[$i] = '\'' . $flipped_array[$i] . '\''; // add surrounding single quotes
}
$name_list = implode(',', $arr);
$query = "SELECT name, COUNT(*) AS cnt FROM table WHERE name IN ($name_list) GROUP BY name HAVING COUNT(*) > 0 ORDER BY name";
$result = mysqli_query($query) or die(mysqli_error());
if (mysqli_num_rows($result) > 0) {
while($row = mysqli_fetch_array($result)) {
echo $quan." ".$row['name']. ": " . $row['cnt'] . PHP_EOL;
}
}
以上查询将仅显示表格中显示的名称。不在表格中的名称将不会显示。现在完整的代码(再次注意SQL注入)