如何从mysql计算所有行，但仅显示2个结果并计算所有结果

Question

I trying to display my data from database. More precisely images. Problem is when i have to extract more than 2 images. Then i want to display only first two images and print for example added 49 images or how many images i had extract from mysql. My script is here:

public function getImages($id, $username){
    global $con;
    $stm = $con->prepare("SELECT * FROM image WHERE postId = :id AND author = :username");
    $stm->execute(array(":id" => $id, ":username" => $username));
    $imagesNum = $stm->rowCount();
    if($imagesNum == 1){
        $image = $stm->fetch(PDO::FETCH_OBJ);
        echo '<div class="frame"><div class="frameOneImage"><img src="../upload/img/'.$username.'/'.$image->path.'"></div></div>';
    } else if($imagesNum == 2){
        echo '<div class="frame">';
        $row = $stm->fetchAll();
        foreach($row as $image){
            echo'<div class="frameTwoImages"><img src="../upload/img/'.$username.'/'.$image['path'].'"></div>';
        }
        echo '</div>';
    } else {
        // HERE I WANT TO DISPLAY ONLY TWO IMAGES BUT IT WRITE ADDED (NUMBER OF ALL IMAGES EXTRACTED)
    }
}

Answer 1

I can think of two ways to achieve that :

First solution

Do a query with a subquery. The main query will return just two rows and the subquery will return the count of total images.

Something like this :

SELECT *, (SELECT COUNT(*) FROM image WHERE postId = :id AND author = :username) as totalRows FROM image WHERE postId = :id AND author = :username LIMIT 2

Second solution

Do your query just like you're doing it right now and do a loop which prints only two images.

 $row = $stm->fetchAll();
 $totalRows = $stm->rowCount();

 // This loop will print only two rows
 for($i = 0; i < 2; $i++) {
     echo $row[$i]; 
 } 
 echo "Total rows " . $totalRows;

Personally I would prefer the first one since it will only returns two rows plus the number of total items in the database instead of the total rows and just printing two of the second solution.

Answer 2

You can set a variable to increment and then exit out of the for loop after two iterations, like so:

else {
    echo '<div class="frame">';
    $row = $stm->fetchAll();
    $i = 0;
    foreach($row as $image){
        echo'<div class="frameTwoImages"><img src="../upload/img/'.$username.'/'.$image['path'].'"></div>';
        if ($i >= 2) {
            echo 'Only first two results showing. ' . $imageNum . ' results have been omitted.';
            break;
        } else {
            $i++;
        }
    }
}

Answer 3

public function getImages($id, $username){
    global $con;
    $stm = $con->prepare("SELECT * FROM image WHERE postId = :id AND author = :username");
    $stm->execute(array(":id" => $id, ":username" => $username));
    $imagesNum = $stm->rowCount();
    $row = $stm->fetchAll();
    for($i=0; $i<2; $i++){
        if(isset($row[$i])){
             echo '<div class="frame"><div class="frame($imagesNum == 1 ? 'OneImage' : 'TwoImages')"><img src="../upload/img/'.$username.'/'.$row[$i]->path.'"></div></div>';
        }
    }
    if($imagesNum > 2) {
        echo '<span>'.$imagesNum.' images total</span>';
    }
}