[英]How to populate a textbox with the appropriate information related to the item selected from a drop down list in PHP?
我正在創建一個表單,該表單允許用戶輸入他們希望在表單中擁有的產品行數。 然后在相應的行中,可以從下拉列表中選擇具有Product_ID和Product_Name的產品。 使用選定的項目,它應從表中拉出Product_Cost並填充“單價”文本框。 我似乎無法使文本框填充正確的數據。 我的if語句if (isset($_POST['product' . $i])){
似乎無法正常工作,它的運行就像該語句為假。 我想說的是“如果選擇框選擇了一個選項,請選擇該選項並在數據庫中找到它的對應行,並獲取該行在該產品中找到的價格,然后填充單價文本框。”
<? require_once("connect_to_DB.php"); //inserts contents of this file here ?>
<!DOCTYPE html>
<html lang="en">
<head>
<title>Order Form</title>
<meta charset="utf-8">
</head>
<body>
<?
connectDB();
$sql = "SELECT * FROM product";
$sql2 = "SELECT DISTINCT emp_id, emp_fname, emp_lname FROM employee";
$sql3 = "SELECT DISTINCT status_id FROM salesorder ORDER BY status_id asc";
$sql4 = "SELECT * FROM salesorder ORDER BY order_id desc";
$result = mysqli_query($db, $sql) or die("SQL error: " . mysqli_error());
$result2 = mysqli_query($db, $sql2) or die("SQL error: " . mysqli_error());
$result3 = mysqli_query($db, $sql3) or die("SQL error: " . mysqli_error());
$result4 = mysqli_query($db, $sql4) or die("SQL error: " . mysqli_error());
//This is for the options in the product list box
$options = '<option value="selectProduct">Select Product</option>';
while($row = mysqli_fetch_array($result,MYSQLI_NUM)){
$options .= '<option value="' . $row[0] . '">' . $row[0] . ' - ' . $row[2] . '</option>';
}
$row2 = mysqli_fetch_array($result2);
$row3 = mysqli_fetch_array($result3);
$row4 = mysqli_fetch_array($result4);
?>
<div id="order-wrap">
<form method="post" action="example.php">
<table class="orderInfo"><br>
<tr>
<th class="textCol">Product Rows:</th>
<td class="inputCol"><input type="text" name="rows"></td>
<td><input class="update" type="submit" name="update" value="Update"></td>
<td class="inputCol"></td>
</tr>
</table>
</form><!-- Order Rows -->
<form class="orderform" action ="order-report.php" METHOD = "post">
<h2>Order Form</h2>
</table>
<!-- Where the product rows input show go ??? -->
<table class="bottomTable">
<tr>
<th class="textCol">Product</th>
<th class="textCol">Quantity</th>
<th class="textCol">Unit Price</th>
<th class="textCol">Total Price</th>
</tr>
<?
if (isset($_POST['update']))
{
//Execute this code if the update button is clicked.
$num = $_POST['rows'];
for ($i=0; $i<$num; $i++) { ?>
<tr>
<td class="inputCol2">
<select name="'product<?= $i ?>'">
<?
echo $options;
?>
</select>
</td>
<td class="inputCol2"><input type="text" name="'quantity<?= $i ?>'" ></td>
<? if (isset($_POST['product' . $i])){ ?>
<td class="inputCol2"><input type="text" name="'unit<?= $i ?>'" value="<?= $row[3] ?>" placeholder="$" ></td>
<? } else { ?>
<td class="inputCol2"><input type="text" name="'unit<?= $i ?>'" value="" placeholder="$"></td>
<? } ?>
<td class="inputCol2"><input type="text" name="'total<?= $i ?>'" placeholder="$"></td>
</tr>
<? } ?>
<tr>
<td class="textCol"></td>
<td class="textCol"></td>
<td class="textCol">Total Order:</td>
<td class="inputCol2"><input type="text" name="totalfinal" placeholder="$"></td>
</tr>
</table>
<input class="submit" type="submit" value="Submit" name="orderSubmit"/>
</form>
<? } else {?>
<tr>
<td class="textCol"></td>
<td class="textCol"></td>
<td class="textCol">Total Order:</td>
<td class="inputCol2">$<input type="text" name="totalfinal"></td>
</tr>
</table>
<input class="submit" type="submit" value="Submit" name="orderSubmit"/>
</form>
<? } ?>
<?
mysqli_free_result($result);
mysqli_free_result($result2);
mysqli_free_result($result3);
mysqli_free_result($result4);
mysqli_close($db);
?>
</div>
</body>
那里似乎有一些語法錯誤,例如:
<select name="'product<?= $i ?>'">
<?
echo $options;
?>
</select>
似乎在某些情況下使用了這種引號-我認為它們應該更像是:
<select name="product<?= $i ?>">
<?
echo $options;
?>
</select>
另外,在某些地方,盡管有人指出不同之處,但您並未為php塊使用正確的開始標記。 通常,它們應該是:
<?php
/* statements */
?>
要么
<?="print out this string";?>
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