Question

使用的代码（已建立数据库连接）：

<?php 
$cur = mysql_query("SELECT MAX(id) FROM trades");
echo "$cur";
while($cur >= 0) {
$query = mysql_query("SELECT * FROM trades WHERE id='$cur'");

if(mysql_num_rows($query)==0) {
    echo "ERROR!";
    exit();
}
$row = mysql_fetch_assoc($query);

$tradeID = $row['ID'];
$mcUsername = $row['Minecraft Username'];
$blockID = $row['Block ID'];
$quantity = $row['Quantity'];
$costPer = $row['CostPer'];
$tradeNotes = $row['TradeNotes'];

    echo "<tr>";
    echo "<td class='first-td'>$tradeID</td>";
    echo "<td>$mcUsername</td>";
    echo "<td>$blockID</td>";
    echo "<td>$quantity</td>";
    echo "<td>$costPer</td>";
    echo "<td class='last-td'>$tradeNotes</td>";
    echo "</tr>";

    $cur = "$cur - 1";
} 
?>

$ cur的回声正在返回：Resource id #7

if语句返回ERROR，这很可能是由于$ cur无法正常工作造成的。

我正在做什么语法错误，因为当我在MySQL DB中手动运行$ cur的SQL查询时，它会返回预期的值。

Answer 1

试试这个

$res = mysql_query("SELECT MAX(id) FROM trades");
$row = mysql_fetch_row($res);
$cur = $row[0];
echo "$cur";

mysql_query返回select查询的资源，而不是值。 Check what is returned by mysql_query and notice the warning against using mysql_ function

返回意外值（MAX（id））

1 个答案: