[英]PHP SQL inner Join bool(false)
我試圖為角色攜帶的物品獲得“總重量”。 我這樣做是通過選擇characteritem表中的項目數量並比較項目表中設置的權重,並通過iid(項目ID)列加入它們
我嘗試了很多不同的方法無濟於事,所以我查找了連接語句。 我遇到的問題是為什么$ result會返回bool(false)然后我如何才能獲得后續加權的權重。
這是我目前正在使用的代碼:
$sql = "SELECT *
FROM `characteritem` WHERE `owner` = '$user'
INNER JOIN item ON characteritem.iid=item.iid";
$result = $db_conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while ($row = $result->fetch_assoc()) {
$iid = $row['characteritem.iid'];
$quantity = $row['characteritem.quantity'];
$itemweight = $row['item.itemweight'];
$itemtotal = $itemweight + $itemweight;
echo $itemtotal;
}
}
var_dump($result);
SQL現在運行正常。 我有重量和數量,並得到了個人的結果。 如何為$ itemtotal獲取值一起添加?
$sql = "SELECT *
FROM `characteritem`
INNER JOIN item ON characteritem.iid=item.iid
WHERE `owner` = '$user'";
$result = $db_conn->query($sql);
if ($result->num_rows > 0) {
while ($row = $result->fetch_assoc()) {
$iid = $row['characteritem.iid'];
$quantity = $row['quantity'];
$itemweight = $row['itemweight'];
$itemtotal = $itemweight * $quantity;
echo $itemtotal;
}
}
Your SQL sintax is wrong, try
$sql = "SELECT *
FROM `characteritem`
INNER JOIN item ON characteritem.iid=item.iid
WHERE `owner` = '$user'";
嘗試這個
$sql = "SELECT *
FROM `characteritem`
INNER JOIN item ON characteritem.iid=item.iid" WHERE `owner` = '$user';
$result = $db_conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while ($row = $result->fetch_assoc()) {
$iid = $row['characteritem.iid'];
$quantity = $row['characteritem.quantity'];
$itemweight = $row['item.itemweight'];
$itemtotal = $itemweight + $itemweight;
echo $itemtotal;
}
}
var_dump($result);
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