MySQL & PHP: querying 3 rows at a time

I'm working on a photo gallery using a database. On each line 3 images are displayed before everything resets. It would be in a <img>/<img>/<img>/<div> format.

我正在使用数据库在照片库上工作。在每一行上,在重置所有内容之前显示3个图像。它将采用 / / /

格式。

So when looking at the source code you'd have:

因此,在查看您拥有的源代码时:

<img src="1" alt="">
<img src="2" alt="">
<img src="3" alt="">
<div class="clear-both"></div>

And it would keep repeating this for every row in the data base. So 9 images would be:

并且它将继续为数据库中的每一行重复此操作。所以9张图片将是:

<img src="1" alt="">
<img src="2" alt="">
<img src="3" alt="">
<div class="clear-both"></div>
<img src="4" alt="">
<img src="5" alt="">
<img src="6" alt="">
<div class="clear-both"></div>
<img src="7" alt="">
<img src="8" alt="">
<img src="9" alt="">
<div class="clear-both"></div>

I figured I could use while to handle this. But I don't know what SQL or PHP statement to add. I thought about using WHERE, GROUP BY and COUNT, but none of these work.

我想我可以用来处理这个问题。但我不知道要添加什么SQL或PHP语句。我想过使用WHERE,GROUP BY和COUNT,但这些都不起作用。

If possible, I also want it to be able to handle rows with just 1 and 2 images. Meaning if there are 4 rows in the table, then it would display:

如果可能的话,我还希望它能够处理只有1和2个图像的行。意思是如果表中有4行,那么它将显示:

<img src="1" alt="">
<img src="2" alt="">
<img src="3" alt="">
<div class="clear-both"></div>
<img src="4" alt="">
<div class="clear-both"></div>

And if there were 8, then it would display:

如果有8,那么它会显示:

<img src="1" alt="">
<img src="2" alt="">
<img src="3" alt="">
<div class="clear-both"></div>
<img src="4" alt="">
<img src="5" alt="">
<img src="6" alt="">
<div class="clear-both"></div>
<img src="7" alt="">
<img src="8" alt="">
<div class="clear-both"></div>

Thanks for the help.

谢谢您的帮助。

PHP

$Database4 = new mysqli("localhost", "user", "pass", "Photography");
$Photos = $Database4 -> query("SELECT *
                               FROM `Year2016`
                               -- ORDER BY DateTaken
                               ;");

while ($DataRows = $Photos -> fetch_array()) {
 echo '<img src="photography/small/' . $DataRows["file"] . '" alt="">' . "\n";
}

echo '<div class="clear-both"></div>' . "\n";

SQL

CREATE TABLE `Year2016`(
 `file` text COLLATE utf8_bin NOT NULL,
)
ENGINE = InnoDB
DEFAULT CHARSET = utf8
COLLATE = utf8_bin;

INSERT INTO `Year2016`(`file`)
VALUES
('red-1.png'),
('red-2.png'),
('red-3.png'),
('red-4.png'),
('red-5.png'),
('red-6.png');

1 个解决方案

#1

This is easy as a pie:

这很简单:

$i = 1;    // special counter
while ($DataRows = $Photos -> fetch_array()) {
    echo '<img src="photography/small/' . $DataRows["file"] . '" alt="">' . "\n";
    if ($i % 3 == 0) {
        echo '<div class="clear-both"></div>';
    }
    $i++;
}
// the last one if last `$i` value is not divided by 3
if ($i % 3 != 1) {
    echo '<div class="clear-both"></div>';
}