即使记录在数据库表中，搜索范围也不会返回任何记录

Question

用户进入我的网页，进入类别范围，它应该返回表中的所有类别，但事实并非如此。我为他们创建了一个页面，以便将记录添加到数据库中的表中并且它可以正常工作。所以现在我需要用户转到搜索页面，并能够查找添加到数据库并显示它们的类别。每当我尝试搜索类别时，一切都运行良好，但它说“没有记录返回”。

 Category Search Look-Up


   <form method="get" action="NameOfFileHere.php">
   Please enter the beginning category: 
   <input type="text" name="BegCat"><br/>
   Enter ending category
   <input type="text" name="EndCat"><br/>

   <input type="submit">
   </form>



       <?php
      $BegCat = htmlentities($_GET["BegCat"]);
      $EndCat = htmlentities($_GET["EndCat"]);

      echo "Trying to return records with category between ". $BegCat ." and       ". $EndCat .".<br/>";

    echo "Connecting to database server.<br />";
    try {
        //variable stores the connection -> $conn
        //PDO is a php data object -> helps prevent SQL injection
        //host = Database server host name
        //username = name of READ ONLY user
        //password = that user's password
        $conn = new PDO("mysql:host=Database Info Here");
    } catch(PDOException $e) { //this should tell us if there was a connection problem
        echo "Error connecting to server: " . $e->getMessage();
        die;
    }
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo "Connection to server succeeded.<br />";
    echo "Connecting to database Category...<br />";
    try {
        //if executing a query, NO USER ENTERED fields should be in query string!
        $conn->query("USE Database Name Here;");
    } catch (PDOException $e) {
        echo "Error connecting to database: " . $e->getMessage();
        die;
    }
    echo "Connection to recipes database succeeded.<br />";
    //SQL statement WILL have any user-entered data, so BIND needed
    $SQL = "SELECT ID, Cat, Description FROM Category";
    $SQL .= " WHERE Cat >= :BegCat AND Cat <= :EndCat;";

    try {
        $sth = $conn->prepare($SQL);
        $sth->bindParam(":BegCat", $BegCat); 
        $sth->bindParam(":EndCat", $EndCat);

        $sth->execute();
    } catch (PDOException $e) {
        echo "Error selecting category records: " . $e->getMessage();
        die;
    }
    echo "Query executed successfully. <br />";
    //are there records in the set?
    if($sth->rowCount()==0) {
        echo "No records returned.<br />";
        die;
    } else {
        echo $sth->rowCount() . " records returned.<br />";
    }
    //$result is an array that holds the dataset
    while($result = $sth->fetch()) {
        //in an array, refer to column with string inside brackets ['rid']
        echo "Category ID: " . $result['ID'] . "<br />";
        echo "Category Name: " . $result['Cat'] . "<br />";
        echo "Description: " . $result['Description'] . "<br />";
        /*put lots link here*/
        echo "<a href='DeleteFileHere.php?ID=".$result['ID']."'>Delete Category ID ".$result['ID']."</a><br />";
        echo "<a href='UpdateFileHere.php?ID=".$result['ID']."'>Update Category ID ".$result['ID']."</a><br />";
    }
    ?>

数据库表的图片 eclipse classes