PHP的搜索引擎的关键字不起作用

Question

When i would search for the keywords that i have specified in my database it will return everything from my database not just the corresponding links that have the keywords attached to the link. here is my code

        <?php
        $q = $_GET['q'];
        $terms = explode(" ", $q);
        $query = "SELECT * FROM search ";

        foreach ($terms as $each){
            $i=0;
            $i++;
                if ($i == 1)
                    $query .= "keywords LIKE '%$each%' ";
                else
                    $query .= "OR keywords LIKE '%$each%' ";

        }

        //connect
        mysql_connect("localhost", "root", "");
        mysql_select_db("search");

        $query = mysql_query("SELECT * FROM search");
        $numrows = mysql_num_rows($query);
        if ($numrows > 0){      

            while($row = mysql_fetch_assoc($query)){
                $id = $row['id'];
                $title = $row['title'];
                $description = $row['description'];
                $keywords = $row['keywords'];
                $link = $row['link'];

                echo "<h3><a href='$link'>$title</a></h3><h4>$link</h4>$description<br /><br />";
            }
        }
        else
            echo "<b>No Results Found</b><br><br>Suggestions:<br>
                Make sure all words are spelled correctly.<br>
                Try different keywords.<br>
                Try more general keywords.";

        //disconnect
        mysql_close();

    ?>

Answer 1

 <?php
    $q = $_GET['q'];
    $terms = explode(" ", $q);

    //connect
    mysql_connect("localhost", "root", "");
    mysql_select_db("search");

    $query = "SELECT * FROM search ";

    $i=1;
    foreach ($terms as $each){
        if ($i == 1) {
            $query .= "WHERE ";
            $query .= "keywords LIKE '" . mysql_real_escape_string("%" . $each . "%") . "' ";
        } else {
            $query .= "OR keywords LIKE '" . mysql_real_escape_string("%" . $each . "%") . "' ";
        }
        $i++;
    }

    $query = mysql_query($query);
    $numrows = mysql_num_rows($query);
    if ($numrows > 0){      

        while($row = mysql_fetch_assoc($query)){
            $id = $row['id'];
            $title = $row['title'];
            $description = $row['description'];
            $keywords = $row['keywords'];
            $link = $row['link'];

            echo "<h3><a href='$link'>$title</a></h3><h4>$link</h4>$description<br /><br />";
        }
    } else {
        echo "<b>No Results Found</b><br><br>Suggestions:<br>
            Make sure all words are spelled correctly.<br>
            Try different keywords.<br>
            Try more general keywords.";
    }
    //disconnect
    mysql_close();

?>

Fixes:

1) Removed second $query that was being defined. It selected all rows.

2) Moved initial $i declaration. It was being set back to 0 each loop.

3) Added WHERE

4) Moved $i++ after the if statement and set initial $i to 1.

5) Added mysql_real_escape_string so that data is escaped properly.

Recommendations:

I highly recommend taking a look at MySQLi ( http://us2.php.net/mysqli ) or PDO ( http://us3.php.net/pdo )

Please let me know if this works or if you need further assistance.

Answer 2

A first sight, i see a couple of errors.

 $i=0;
 $i++;
     if ($i == 1)

$i Will ALWAYS be one are. you might want to move $i = 0; BEFORE the foreach

$query = mysql_query("SELECT * FROM search");

You build a query, but in the end you're not using it. you probably want to do : $query = mysql_query($query); instead. ( and also for code clarity using a different variable name for the output ? ) .

mysql_query is deprecated. Useless you're in a hurry, check PDO

Answer 3

First, you're missing the WHERE keyword before the conditions. So it should be:

    foreach ($terms as $i => $each){
        $each = mysql_real_escape_string($each); // Prevent SQL injection
        if ($i == 0)
            $query .= "WHERE keywords LIKE '%$each%' ";
        else
            $query .= "OR keywords LIKE '%$each%' ";

    }

You don't need to increment your own counter variable, you can use the array indexes from $terms .

Second, after all that work to create $query , you're not using it. You wrote:

    $query = mysql_query("SELECT * FROM search");

That should be:

    $query = mysql_query($query);

BTW, it's generally a bad idea to reuse variables like that, it gets confusing when you use the same variable for different things. I suggest you call the second $query something like $results .

Answer 4

Change this line

$query .= "keywords LIKE '%$each%' ";

By

$query .= " Where keywords LIKE '%$each%' ";

And also cnhange this line

$query = mysql_query("SELECT * FROM search");

By

$query = mysql_query($query);