我正在尝试使用一种表格来搜索汽车数据库。当有人选择“任何”时，我希望表格显示该字段的所有选项，但是当有人选择特定选项时，我希望表格显示仅具有该选项值的汽车。下面的代码显示了到目前为止的内容，但未显示任何结果。任何建议将不胜感激。谢谢。
carSearch.php
<form id="searchForm" class="form" method="POST" action="results.php">
<div class="form-group">
<label for="make" class="mr-sm-2">Make:</label>
<select class="form-control mb-2 mr-sm-2" name="make" id="make"></select>
</div>
<div class="form-group">
<label for="model" class="mr-sm-2">Model:</label>
<select class="form-control mb-2 mr-sm-2" name="model" id="model"></select>
</div>
<div class="form-group">
<label for="bodyType" class="mr-sm-2">Body Type:</label>
<select class="form-control mb-2 mr-sm-2" name="bodyType" id="bodyType">
<option value="`Body Type`">Any</option>
<option value="Convertible">Convertible</option>
<option value="Coupe">Coupe</option>
<option value="Hatch">Hatch</option>
<option value="Sedan">Sedan</option>
<option value="SUV">SUV</option>
<option value="Wagon">Wagon</option>
</select>
</div>
<div class="form-group">
<label for="minPrice" class="mr-sm-2">Minimum Price:</label>
<select class="form-control mb-2 mr-sm-2" name="minPrice" id="minPrice">
<option value="50000">Any</option>
<option value="50000">$50,000</option>
<option value="100000">$100,000</option>
<option value="150000">$150,000</option>
<option value="200000">$200,000</option>
<option value="250000">$250,000</option>
<option value="300000">$300,000</option>
<option value="350000">$350,000</option>
<option value="400000">$400,000</option>
<option value="450000">$450,000</option>
<option value="500000">$500,000</option>
<option value="550000">$550,000</option>
<option value="600000">$600,000</option>
<option value="650000">$650,000</option>
<option value="700000">$700,000</option>
<option value="750000">$750,000</option>
<option value="800000">$800,000</option>
<option value="850000">$850,000</option>
<option value="900000">$900,000</option>
</select>
</div>
<div class="form-group">
<label for="maxPrice" class="mr-sm-2">Maximum Price:</label>
<select class="form-control mb-2 mr-sm-2" name="maxPrice" id="maxPrice">
<option value="900000">Any</option>
<option value="50000">$50,000</option>
<option value="100000">$100,000</option>
<option value="150000">$150,000</option>
<option value="200000">$200,000</option>
<option value="250000">$250,000</option>
<option value="300000">$300,000</option>
<option value="350000">$350,000</option>
<option value="400000">$400,000</option>
<option value="450000">$450,000</option>
<option value="500000">$500,000</option>
<option value="550000">$550,000</option>
<option value="600000">$600,000</option>
<option value="650000">$650,000</option>
<option value="700000">$700,000</option>
<option value="750000">$750,000</option>
<option value="800000">$800,000</option>
<option value="850000">$850,000</option>
<option value="900000">$900,000</option>
</select>
</div>
<div class="form-group">
<label for="driveType" class="mr-sm-2">Drive Type:</label>
<select class="form-control mb-2 mr-sm-2" name="driveType" id="driveType">
<option value="`Drive Type`">Any</option>
<option value="4WD">4WD</option>
<option value="AWD">AWD</option>
<option value="RWD">RWD</option>
</select>
</div>
<div class="form-group">
<label for="doors" class="mr-sm-2">Doors:</label>
<select class="form-control mb-2 mr-sm-2" name="doors" id="doors">
<option value="`Doors`">Any</option>
<option value="2">2</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="7">7</option>
</select>
</div>
<div class="form-group">
<label for="seats" class="mr-sm-2">Seats:</label>
<select class="form-control mb-2 mr-sm-2" name="seats" id="seats">
<option value="`Seats`">Any</option>
<option value="2">2</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="7">7</option>
</select>
</div>
<div class="form-group">
<label for="fuelType" class="mr-sm-2">Fuel Type:</label>
<select class="form-control mb-2 mr-sm-2" name="fuelType" id="fuelType">
<option value="`Fuel Type`">Any</option>
<option value="Petrol">Petrol</option>
<option value="Diesel">Diesel</option>
<option value="Hybrid">Hybrid</option>
<option value="Electric">Electric</option>
</select>
</div>
<div class="form-group">
<label for="cylinders" class="mr-sm-2">Cylinders:</label>
<select class="form-control mb-2 mr-sm-2" name="cylinders" id="cylinders">
<option value="`Cylinders`">Any</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="8">8</option>
<option value="10">10</option>
<option value="12">12</option>
</select>
</div>
<div class="form-group">
<label for="minEngineSize" class="mr-sm-2">Minimum Engine Size:</label>
<select class="form-control mb-2 mr-sm-2" name="minEngineSize" id="minEngineSize">
<option value="1000">Any</option>
<option value="1000">1,000</option>
<option value="2000">2,000</option>
<option value="3000">3,000</option>
<option value="4000">4,000</option>
<option value="5000">5,000</option>
<option value="6000">6,000</option>
<option value="7000">7,000</option>
</select>
</div>
<div class="form-group">
<label for="maxEngineSize" class="mr-sm-2">Maximum Engine Size:</label>
<select class="form-control mb-2 mr-sm-2" name="maxEngineSize" id="maxEngineSize">
<option value="7000">Any</option>
<option value="1000">1,000</option>
<option value="2000">2,000</option>
<option value="3000">3,000</option>
<option value="4000">4,000</option>
<option value="5000">5,000</option>
<option value="6000">6,000</option>
<option value="7000">7,000</option>
</select>
</div>
<button type="submit" class="btn btn-danger mb-2 submitButton">GO! >></button>
</form>
results.php
<table id="carsTable">
<?php
$mysqli = new mysqli("localhost", "***", "***", "***");
if ($mysqli->connect_errno) {
printf("Connect failed: %s\n", $mysqli->connect_error);
exit();
}
$make = mysqli_real_escape_string($mysqli, $_POST['make']);
$model = mysqli_real_escape_string($mysqli, $_POST['model']);
$bodyType = mysqli_real_escape_string($mysqli, $_POST['bodyType']);
$minPrice = mysqli_real_escape_string($mysqli, $_POST['minPrice']);
$maxPrice = mysqli_real_escape_string($mysqli, $_POST['maxPrice']);
$driveType = mysqli_real_escape_string($mysqli, $_POST['driveType']);
$doors = mysqli_real_escape_string($mysqli, $_POST['doors']);
$seats = mysqli_real_escape_string($mysqli, $_POST['seats']);
$fuelType = mysqli_real_escape_string($mysqli, $_POST['fuelType']);
$cylinders = mysqli_real_escape_string($mysqli, $_POST['cylinders']);
$minEngineSize = mysqli_real_escape_string($mysqli, $_POST['minEngineSize']);
$maxEngineSize = mysqli_real_escape_string($mysqli, $_POST['maxEngineSize']);
if ($make = "Any") {
$make = "`Make`";
}
if ($model = "Any") {
$model = "`Model`";
}
/*Create table doesn't return a resultset*/
if ($mysqli->query("CREATE TEMPORARY TABLE kenscars LIKE cars") === FALSE) {
printf("Creation of Table Cars Unsuccessful.\n");
}
$sql = "SELECT * FROM cars WHERE `Make`='$make' AND `Model`=$model AND `Body Type`=$bodyType AND (`Price` BETWEEN $minPrice AND $maxPrice) AND `Drive Type`=$driveType AND `Doors`=$doors AND `Seats`=$seats AND `Fuel Type`=$fuelType AND `Cylinders`=$cylinders AND (`Engine Size` BETWEEN $minEngineSize AND $maxEngineSize) ORDER BY `Make`, `Model`";
$results = $mysqli->query($sql);
if (!$results) {
printf("Error: %s\n", mysqli_error($mysqli));
exit();
}
while($row = mysqli_fetch_array($results)) {
?>
<tr>
<td style="text-align:center;">
<strong><span class="carTitle"><?php echo $row['Year']?> <?php echo $row['Make']?> <?php echo $row['Model']?></span></strong>
<br>
<br>
<img src="Images/Cars/<?php echo $row['Image']?>" width="80%">
<br>
<br>
<form id="enquireForm" class="form" method="POST" action="carEnquiry.php">
<input type="hidden" name="enquiryCar" id="enquiryCar" value="<?php echo $row['Year']?> <?php echo $row['Make']?> <?php echo $row['Model']?>">
<button type="submit" class="btn btn-danger btn-block mb-2">ENQUIRE NOW! >></button>
</form>
</td>
<td>
<table id="innerCarsTable">
<tr>
<th class="header">Price:</th>
<td>$<?php echo $row['Price']?></td>
</tr>
<tr>
<th class="header">Body Type:</th>
<td><?php echo $row['Body Type']?></td>
</tr>
<tr>
<th class="header">Drive Type:</th>
<td><?php echo $row['Drive Type']?></td>
</tr>
<tr>
<th class="header">Fuel Type:</th>
<td><?php echo $row['FuelType']?></td>
</tr>
<tr>
<th class="header">Fuel Efficiency:</th>
<td><?php echo $row['Fuel Efficiency']?>L/100km</td>
</tr>
<tr>
<th class="header">Transmission:</th>
<td><?php echo $row['Transmission']?></td>
</tr>
<tr>
<th class="header">Doors:</th>
<td><?php echo $row['Doors']?></td>
</tr>
<tr>
<th class="header">Seats:</th>
<td><?php echo $row['Seats']?></td>
</tr>
<tr>
<th class="header">Cylinders:</th>
<td><?php echo $row['Cylinders']?></td>
</tr>
<tr>
<th class="header">Engine Capacity:</th>
<td><?php echo $row['Engine Capacity']?>L</td>
</tr>
<tr>
<th class="header">Engine Size:</th>
<td><?php echo $row['Engine Size']?>cc</td>
</tr>
<tr>
<th class="header">Power:</th>
<td><?php echo $row['Power']?></td>
</tr>
<tr>
<th class="header">Torque:</th>
<td><?php echo $row['Torque']?></td>
</tr>
</table>
<br>
</td>
</tr>
<?php
}
?>
</table>