我必须在下拉列表预览中显示一个选定的选项，但目前从数据库中提取值时，它只显示一个选项，而不显示数据库中的另一个选项。
当从数据库(PgAdmin)中提取已知值时，有没有办法显示实际的下拉列表选项(所有代码都是HTML、CSS或PHP)
基本上，我希望它将数据库中的值显示为下拉菜单中的选定选项，正如您可能在我尝试过的以下代码中看到的那样，但我不太确定如何从这一点进一步推进。也可以随时更正我代码中的错误。我知道这有点难消化，但希望很快就能得到答案：)
<?php
$conn = pg_connect("host=localhost port=5432 dbname=cafe user=postgres password=password");
if(count($_POST)>0) {
pg_query($conn,"UPDATE cakesweetorder set id='$_POST[id]',
firstname='$_POST[firstname]',
surname='$_POST[surname]',streetno='$_POST[streetno]',
streetname='$_POST[streetname]',
state = '$_POST[state]', suburb='$_POST[suburb]',
postcode='$_POST[postcode]', email='$_POST[email]',
mobno='$_POST[mobno]',colour='$_POST[colour]',
toping='$_POST[toping]',
chocosentence='$_POST[chocosentence]',
quantity='$_POST[quantity]', date='$_POST[date]',
file='$_POST[file]',
tea='$_POST[tea]'
WHERE id='$_POST[id]' ");
$message = "Record Modified Successfully";
}
$result = pg_query($conn,"SELECT * FROM cakesweetorder WHERE id='" . $_GET['id'] . "'");
$row= pg_fetch_array($result);
?>
<html>
<head>
<?php
include_once 'head.php';
?>
<p>
<div class='text-box'>
<div class='wrapper-glass'>
<div class='shape-1'></div>
<div class='shape-2'></div>
<div class='shape-3'></div>
<div class='shape-4'></div>
<div class='shape-5'></div>
<div class='shape-6'></div>
<div class='shape-7'></div>
<div class='shape-8'></div>
<div class='shape-9'></div>
<div class='shape-10'></div>
<div class='container-glass'>
<title>Cafe Database</title>
</head>
<body>
<form name="frmUser" method="post" action="">
<div><?php if(isset($message)) { echo $message; }
?>
</div>
ID: <br>
<input type="hidden" name="id" class="txtField" value="<?php echo $row['id']; ?>">
<input readonly='readonly' name="id" value="<?php echo $row['id']; ?>">
<br>
<legend>Name</legend>
Firstname:<div class="bar"><div class="text-bar"><input type="text" class="form-control" name="firstname" id="name" placeholder="Firstname..." value="<?php echo $row['firstname']; ?>"required/></div></div>
Surname:<div class="bar"><div class="text-bar2"><input type="text" class="form-control" name="surname" id="name" placeholder="Surname..." value="<?php echo $row['surname']; ?>"required/></div></div>
<legend>Address For Delivery</legend>
Street No: <div class="bar"><div class="text-bar3"><input type="number" id="text-bar" class="form-control" name="streetno" placeholder="Street No..." value="<?php echo $row['streetno']; ?>"required/><br/></div></div>
Street: <div class="bar"><div class="text-bar4"><input type="text" id="text-bar" class="form-control" name="streetname" placeholder="Street Name..." value="<?php echo $row['streetname']; ?>"required/><br/></div></div>
State:
State:
<div class="bar"><div class="text-bar5"><select id="state" class="form-control" name="state" value="<?php echo $row['state']; ?>" name="state"></div></div>
<optgroup label="States">
<option value="NSW">NSW</option>
<option value="QLD">QLD</option>
<option value="VIC">VIC</option>
<option value="SA">SA</option>
<option value="NT">NT</option>
<option value="TAS">TAS</option>
</select><br></div></div>
Suburb: <div class="bar"><div class="text-bar6"><input type="text" class="form-control" name="suburb" placeholder="Suburb..." value="<?php echo $row['suburb']; ?>" required/><br/></div></div>
Postcode: <div class="bar"><div class="text-bar7"><input type="number" class="form-control" name="postcode" placeholder="Postcode..." value="<?php echo $row['postcode']; ?>" required/><br/></div></div>
<legend>Personal Details</legend>
Email:<div class="bar"><div class="text-bar8"> <input type="email" class="form-control" name="email" placeholder="Email..." value="<?php echo $row['email']; ?>" required/><br/></div></div>
Phone Number: <div class="bar"><div class="text-bar9"><input type="number" class="form-control" name="mobno" placeholder="Phone Number..." value="<?php echo $row['mobno']; ?>"required/><br/></div></div>
Colour of Cake: <div class="input-color-container">
<div class="bar"><div class="text-bar11"><input id="input-color" name="colour" class="input-color" type="color" value="<?php echo $row['colour']; ?>"></div></div>
</div>
<label class="input-color-label" for="input-color">
</label>
Topings: <br><br>
<label class="checkbox-container">
<input type="checkbox" name="toping" <?php if(isset($_POST['toping']) && $_POST['toping'] = 'Vanilla') echo "checked" ?> value="<?php echo $row['toping']; ?>"><span class="checkmark"></span><span class="checkbox-txt"> Vanilla</span><br/></br></label>
<label class="checkbox-container">
<input type="checkbox" name="toping" <?php if(isset($_POST['toping']) && $_POST['toping'] = 'Chocolate') echo "checked" ?> value="<?php echo $row['toping']; ?>"><span class="checkmark"></span><span class="checkbox-txt" >Chocolate</span><br/></br></label>
<label class="checkbox-container">
<input type="checkbox" name="toping" <?php if(isset($_POST['toping']) && $_POST['toping'] = 'Caramel') echo "checked" ?> value="<?php echo $row['toping']; ?>"><span class="checkmark"></span><span class="checkbox-txt" >Caramel</span><br/></br></label>
<label class="checkbox-container">
<input type="checkbox" name="toping" <?php if(isset($_POST['toping']) && $_POST['toping'] = "Strawberry") echo "checked" ?> value="<?php echo $row['toping']; ?>"><span class="checkmark"></span><span class="checkbox-txt" >Strawberry</span><br/></br></label>
<label class="checkbox-container">
<input type="checkbox" name="toping" <?php if(isset($_POST['toping']) && $_POST['toping'] = "M&M's") echo "checked" ?> value="<?php echo $row['toping']; ?>"><span class="checkmark"></span><span class="checkbox-txt" >M&M's</span><br/></br></label>
<label class="checkbox-container">
<input type="checkbox" name="toping" <?php if(isset($_POST['toping']) && $_POST['toping'] = "Oreo") echo "checked" ?> value="<?php echo $row['toping']; ?>"><span class="checkmark"></span><span class="checkbox-txt" >Oreo</span><br/></br></label>
<label class="checkbox-container">
<input type="checkbox" name="toping" <?php if(isset($_POST['toping']) && $_POST['toping'] = "Meringue") echo "checked" ?> value="<?php echo $row['toping']; ?>"><span class="checkmark "></span><span class="checkbox-txt" >Meringue</span><br/></label>
Chocolate Sentences: <div class="bar"><div class="text-bar12"><input type="text" class="form-control" name="chocosentence" placeholder="Chocolate sentence..." value="<?php echo $row['chocosentence']; ?>"/><br/></div></div>
Quantity of Cakes or Sweets: <div class="bar"><div class="text-bar13"><input type="number" class="form-control" min="1" value="1" max="10" name="quantity" placeholder="Quantity..." value="<?php echo $row['quantity']; ?>" required/><br/></div></div>
Complimentary Tea: <br>
<div class="container">
<input type="radio" name="tea" value="true" <?php if(isset($_POST['tea']) && $_POST['tea'] = 't') echo "checked" ?>value="<?php echo $row['tea']; ?>">
<label for="tea" class="label1">
<span>YES</span>
</label>
<input type="radio" name="tea" <?php if(isset($_POST['tea']) && $_POST['tea'] = 'f') echo "checked" ?>value="<?php echo $row['tea']; ?>">
<label for="tea" class="label2">
<span>NO</span>
</label>
</div>
<br><br><br><br><br>
<legend>Miscellaneos</legend>
Date Of Delivery: <div class="bar"><div class="text-bar14"><input type="date" class="form-control" name="date" placeholder="Date of Delivery..." value="<?php echo $row['date']; ?>" required/><br/><br><br></div></div>
Custom Order with Instructions: <input type="file" class="form-control" name="file" placeholder="Custom Order..." /><br/>
OR Type in Instructions:
<div class="container3">
<div class="bar"><div class="text-bar15"><textarea id="my-text" name="file" rows="5" placeholder="Type Custom Order Here.." value="<?php echo $row['file']; ?>" ></textarea>
<p id="result"></p>
</div></div></div>
<br>
<input type="submit" name="submit" class='signup-btn' value="Submit" class="button">
</form>
</body>
</html>TAS</option>
</select><br></div></div>’
我尝试过这样的东西，但它并没有真正起作用：(下面)，这是一个非常模糊的尝试，但正如我之前所说的，它不起作用，我真的无法弄清楚
`<?php
$db = pg_connect("host=localhost port=5432 dbname=SRIS user=postgres password=password");
$result = pg_query($db, "SELECT * FROM customer where customer_id = '$_POST[customer_id]'");
$row = pg_fetch_assoc($result);
// isset is set to submit in line 14
if (isset($_POST['submit']))
{
if ($row[pref_gender] == 'M') {
echo "</br>";
$statement1 = "<option value='M' selected>Male</option>
<option value='F'>Female</option>";
}
if ($row[pref_gender] == 'F') {
echo "</br>";
$statement1 = "<option value='F' selected>Female</option>
<option value='M'>Male</option>";
}
// retrieves one row of data from the table and displays the fields in the form
// Book id is a primary key so we can't edit it
echo "<p>
<form name='update' action='enter_primarykey.php' method='POST' >
<li>Customer Id</li><li><input type='text' name='customer_id_updated' value='$row[customer_id]' /></li>
<li>Firstname</li><li><input type='text' name='firstname_updated' value='$row[firstname]' /></li>
<li>Surname</li><li><input type='text' name='surname updated' value='$row[surname]' /></li>
<li>Gender</li>
<li>
<select name='pref_gender_updated'>
$statement1
</select>
</li>
<li><input type='submit' name='new' /></li> </form>
</p>";
}
// isset is set to new in line 37
// uses the primary key to save all the values back into the database when submit is clicked
if (isset($_POST['new']))
{
$result1 = pg_query($db, "UPDATE customer SET firstname = '$_POST[firstname_updated]',
surname = '$_POST[surname_updated]', pref_gender = '$_POST[pref_gender_updated]' WHERE customer_id= '$_POST[customer_id_updated]'”);`
下面是我想要改变的。当显示从表中提取的数据时，我希望它显示"QLD"，而不是显示默认的"NSW"，我如何调整代码来做到这一点？
`State:
<div class="bar"><div class="text-bar5"><select id="state" class="form-control" name="state" value="<?php echo $row['state']; ?>" name="state"></div></div>
<optgroup label="States">
<option value="NSW">NSW</option>
<option value="QLD">QLD</option>
<option value="VIC">VIC</option>
<option value="SA">SA</option>
<option value="NT">NT</option>
<option value="TAS">TAS</option>
</select><br></div></div>`
它看起来有点像这样：
PHP
//Do Query (In your case, we can use $row['states']
HTML
`State:
<div class="bar">
<div class="text-bar5">
<select id="state" class="form-control" name="state" name="state"></div></div>
<optgroup label="States">
<option value="NSW" <?php if($row['states'] == 'NSW')echo 'selected'; ?> >NSW</option>
<option value="QLD" <?php if($row['states'] == 'QLD')echo 'selected'; ?> >QLD</option>
<!-- VIC will be selected -->
<option value="VIC" <?php if($row['states'] == 'VIC')echo 'selected'; ?> >VIC</option>
<!-- VIC will be selected -->
<option value="SA" <?php if($row['states'] == 'SA')echo 'selected'; ?> >SA</option>
<option value="NT" <?php if($row['states'] == 'NT')echo 'selected'; ?> >NT</option>
<option value="TAS" <?php if($row['states'] == 'TAS')echo 'selected'; ?> >TAS</option>
</select><br>
</div>
</div>`
您可以用非常简单的方法来完成。
<?php $row= ("Your SQL QUERY WITH CONNECTION AND EXECUTION"); ?>
<div>
<div>
<select id="select_state" name="state" name="state"></div></div>
<optgroup label="States">
<option value="NSW" <?php if($row['states'] == 'NSW')echo 'selected'; ?> >NSW</option>
<option value="QLD" <?php if($row['states'] == 'QLD')echo 'selected'; ?> >QLD</option>
<option value="VIC" <?php if($row['states'] == 'VIC')echo 'selected'; ?> >VIC</option>
<option value="SA" <?php if($row['states'] == 'SA')echo 'selected'; ?> >SA</option>
<option value="NT" <?php if($row['states'] == 'NT')echo 'selected'; ?> >NT</option>
<option value="TAS" <?php if($row['states'] == 'TAS')echo 'selected'; ?> >TAS</option>
</select><br>
</div>
</div>这似乎也奏效了！
PHP
$result = pg_query($conn,"SELECT * FROM cakesweetorder WHERE id='" . $_GET['id'] . "'");
$row= pg_fetch_array($result);
if ($row['state'] == 'NSW') {
echo "</br>";
$statement1 = "<option value='NSW' selected>NSW</option>
<option value='QLD'>QLD</option>
<option value='VIC' >VIC</option>
<option value='SA'>SA</option>
<option value='NT'>NT</option>
<option value='TAS'>TAS</option>";
}
if ($row['state'] == 'QLD') {
echo "</br>";
$statement1 = "<option value='QLD' selected>QLD</option>
<option value='NSW'>NSW</option>
<option value='VIC' >VIC</option>
<option value='SA'>SA</option>
<option value='NT'>NT</option>
<option value='TAS'>TAS</option>";
}
if ($row['state'] == 'VIC') {
echo "</br>";
$statement1 = "<option value='VIC' selected>VIC</option>
<option value='NSW' >NSW</option>
<option value='QLD'>QLD</option>
<option value='SA'>SA</option>
<option value='NT'>NT</option>
<option value='TAS'>TAS</option>";
}
if ($row['state'] == 'SA') {
echo "</br>";
$statement1 = "<option value='SA' selected>SA</option>
<option value='NSW'>NSW</option>
<option value='QLD'>QLD</option>
<option value='VIC'>VIC</option>
<option value='NT'>NT</option>
<option value='TAS'>TAS</option>";
}
if ($row['state'] == 'NT') {
echo "</br>";
$statement1 = " <option value='NT' selected>NT</option>
<option value='NSW'>NSW</option>
<option value='QLD'>QLD</option>
<option value='VIC'>VIC</option>
<option value='SA'>SA</option>
<option value='TAS'>TAS</option>";
}
if ($row['state'] == 'TAS') {
echo "</br>";
$statement1 = "<option value='TAS' selected>TAS</option>
<option value='NSW'>NSW</option>
<option value='QLD'>QLD</option>
<option value='VIC'>VIC</option>
<option value='SA'>SA</option>
<option value='NT'>NT</option>"
;
}
HTML
State: <br>
<select id='state' class='form-control' name='state'>
$statement1
</select>
"