PHP减少数据库上的重复连接

Question

i am using 3 different functions that connect on my MySQL 1th one - Check if there is any result in database for string 2th one - Display some values based on searched string 3th one - Insert some info about search to logs

So in general First 2 seartch same table and make duplicity , and 3th one connect on same database as well just different table. I really start thinking that its not the way my script should work. Because tables are pretty big and it takea time for script to search it. So if i make duplicity it take just 2x longer what is pointless, can somebody give me some advises how can i edit it to make it faster or avoid this without security issues?

In general i create 2x connection on datbase:

data.php

 public function fetchByVinEvidenceDetail($con) {
     $success = false;
     try{
        $sql = "SELECT * FROM evidence_calculations WHERE vin = :vin LIMIT 5";
        $stmt = $con->prepare( $sql );
        $stmt->bindValue( "vin", $this->vin, PDO::PARAM_STR );
        $stmt->execute();
        echo $this->vin;
            while ($row = $stmt->fetch()){
                echo "<tr>";
                echo "<br>#4";
                echo "<br>".$row['street'];
                echo "<br>".$row['city'];
                echo "<br>".$row['claim_number'];
                echo "<br>".$row['company'];
                echo "<br>".$row['country'];
                echo "<br>".$row['other'];
                echo "<br>".$row['parts'];
                echo "<br>".$row['labor'];
                echo "<br>".$row['calculation_start'];
                echo "<br> -------------------------------- <br>";
            }
            }catch(PDOExeption $e){
            echo $e->getMessage();
            echo $con->errorInfo();
            }

         return $success; 
     }                   

     public function ExistVinEvidence() {
     $success = false;
     try{
        $con = new PDO( DB_HOST, DB_USER, DB_PASS ); 
        $con->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
        $sql = "SELECT * FROM evidence_calculations WHERE vin = :vin LIMIT 30";
        $stmt = $con->prepare( $sql );
        $stmt->bindValue( "vin", $this->vin, PDO::PARAM_STR );
        $stmt->execute();
        $count = $stmt->rowCount();
        if ($count>0){
            echo 'For VIN:<b>'.$this->vin.'</b> we found '.$count.' rows in our far history database.</a> <br>';
        }
        else
        {
             echo 'We are sorry but we didnt find any data for VIN <b> '.$this->vin.' in far history database</b> <br>';
        }
        }catch(PDOExeption $e){
         echo $e->getMessage();
         echo $con->errorInfo();
        }
 }

 public function searchLog() {
    $correct = false;
        try {
            $date = new DateTime();
            $con = new PDO( DB_HOST, DB_USER, DB_PASS );
            $con->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
            $sql = "INSERT INTO search_log(vin, date, user, ip, search_directory) VALUES(:vin, :date, :user, :ip, :search_directory)";

            $stmt = $con->prepare( $sql );
            $stmt->bindValue( "vin", $this->vin, PDO::PARAM_STR );
            $stmt->bindValue( "date", $date->getTimestamp(), PDO::PARAM_STR );
            $stmt->bindValue( "user", $this->getUsername(), PDO::PARAM_STR );
            $stmt->bindValue( "ip", $this->getUserIP(), PDO::PARAM_STR );
            $stmt->bindValue( "search_directory", "1", PDO::PARAM_STR );
            $stmt->execute();
            return "Logged";
        }catch( PDOException $e ) {
            return $e->getMessage();
        }
 }

sql.php (which i include_once to data.php)

  $con = new PDO( DB_HOST, DB_USER, DB_PASS ); 
        $con->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );

index.php

                    $data = new Data;
                    $data->storeFormValues( $_POST );
                    $data->fetchByVinEvidence();
                    $data->ExistVinEvidence();

and it throw error UNDEFINED $con

Answer 1

Open one time the connection to the database, and pass the $con parameter to your functions:

$con = new PDO( DB_HOST, DB_USER, DB_PASS );
$con->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );

searchLog($con);
fetchByVinEvidenceDetail($con);
ExistVinEvidence($con);

And searchLog :

public function searchLog($con) {
    $correct = false;
    try {
        $date = new DateTime();
        $sql = "INSERT INTO search_log(vin, date, user, ip, search_directory) VALUES(:vin, :date, :user, :ip, :search_directory)";

        $stmt = $con->prepare( $sql );
        ...

Answer 2

You will want to use the Singleton pattern to return a single instance of your PDO object throughout your application.

see : http://en.wikipedia.org/wiki/Singleton_pattern

Link to PHP implementation of singleton pattern:

http://www.phptherightway.com/pages/Design-Patterns.html