查询多个 SQL 表，并从单个 HTML 页中的一个或多个表返回结果

我想使用 PHP 和 SQL 查询多个表，并在单个 HTML 页面中返回格式。

这是我目前得到的：

.HTML：

<form name="searchForm" method="POST" action=""> <!-- My new PHP file would go here -->
  Search for: <input type="text" name="aSearch"> 
  <input type="submit" name="searchButton" value="Search">
</form>

控制器 1 (PHP(：

// Connect to DB
$servername = "";
$username = "";
$password = "";
$dbname = "";
// Create connection
$conn = new MySQLi($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
}

// Collect Data phase:
// If an input has been given remove unnecessary characters
if(isset($_POST["aSearch"])) {
  $searchq = $_POST["aSearch"]; //searchq allows the input to search for part of a word
  $searchq = preg_replace("#[^0-9a-z]#i","",$searchq); //Can only search words
// Select statements if the searched word and insectName match
$sql = "SELECT * FROM insectt WHERE insectName LIKE '%$searchq%'";
}
// Tests if the code been inserted
if ($conn->query($sql)=== TRUE){
  echo "The rows you have searched for are:";
} else {
  echo "Connection failed: ";
  echo $conn->error;
}
// Show fields
$result = $conn->query($sql);
// Output data of each row
if ($result-> num_rows> 0) {
  readfile("ViewReturn.html"); //Output it in an html file
  while($row = $result-> fetch_assoc()) {
    echo "Insect Name: ".$row["insectName"]. "<br><br>";
  }
} else {
  echo "0 results";
}
// Close connections
if (!function_exists('mysqli_init') && !extension_loaded('mysqli')) {
  echo "There was an error with MySQLi";
} else {
  echo "Closing Connections";
}
$conn-> close();
exit();
?>

控制器 2 (PHP(：

// Connect to DB
$servername = "";
$username = "";
$password = "";
$dbname = "";
// Create connection
$conn = new MySQLi($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
}
// Collect Data phase:
// If an input has been given remove unnecessary characters
if(isset($_POST["aSearch"])) {
  $searchq = $_POST["aSearch"]; //searchq allows the input to search for part of a word
  $searchq = preg_replace("#[^0-9a-z]#i","",$searchq); //Can only search words
// Select statements if searched
$sql = "SELECT * FROM birdt WHERE birdName LIKE '%$searchq%'";
}
// Tests if the code been inserted
if ($conn->query($sql)=== TRUE){
  echo "The rows you have searched for are:";
} else {
  echo "Connection failed: ";
  echo $conn->error;
}
// Show fields
$result = $conn->query($sql);
// Output data of each row
if ($result-> num_rows> 0) {
  readfile("ViewReturn.html"); //Output it in an html file
  while($row = $result-> fetch_assoc()) {
    echo "Bird Name: ".$row["birdName"]. "<br><br>";
  }
} else {
  echo "0 results";
}
// Close connections
if (!function_exists('mysqli_init') && !extension_loaded('mysqli')) {
  echo "There was an error with MySQLi";
} else {
  echo "Closing Connections";
}
$conn-> close();
exit();
?>

SQL 表：

birdt:                    insectt:
╔════════╦═══════════╗    ╔══════════╦════════════╗ 
║ birdID ║  birdName ║    ║ insectID ║ insectName ║
╠════════╬═══════════╣    ╠══════════╬════════════╣
║   1    ║   Gull    ║    ║    1     ║   cricket  ║
║   2    ║   Hawk    ║    ║    2     ║   bee      ║
║   3    ║   Pigeon  ║    ║    3     ║   flea     ║
╚════════╩═══════════╝    ╚══════════╩════════════╝

目前，我可以通过更改HTML表单中的操作(我可以从下拉列表中执行此操作(来分别搜索两个表，并在不同的HTML页面中分别返回查询结果，但仅此而已。

我想知道的是，是否有办法从单个控制器查询两个SQL表(并将其作为我的html表单中的新控制器(，它可以查询我的两个表并在单个HTML页面中返回搜索结果。因此，如果我要搜索与鸟或插图表中的记录名称匹配的单个关键字 - 或两者兼而有之 - 它将返回它。

可能需要更改的是我的 PHP 文件中的 SQL 查询，但我不确定将其更改为什么。

我真的不知道该怎么做，网上的信息很混乱，所以我会接受任何帮助。

提前感谢您的任何帮助。