How to add pictures to database in php

In order to ensure high availability, Baidu Developer's Cloud Code Space does not allow users to save images into the code space. Using CDN or object storage is not only chargeable but also complicated to use, so we considered it. Whether to store img in the database, although many people say it will cause performance problems, you should give it a try.

1. Prepare three files

The first one is used to store pictures as database characters, and the second one is used to store pictures as database characters. The first php file is used to obtain database characters and generate images, and the third one is the image used in file 1.

2. Database design

Extra long strings or binary data can be saved using TEXT (65535) and BLOB (64k) respectively, but attempts to save using binary failed. I use TEXT to save it, but a base64-encrypted picture of more than 500 kb has a character length of 750,000!

Just one TEXT cannot be saved, and it may also cause serious performance problems, so it is divided into N parts and saved. Here, the length of 50,000 characters is used as a unit. Record imgid to facilitate splicing.

3. Save the image to the database [dm01_imgTobase64.php]

/*链接数据库*/

// 1.转为普通字符
$file = file_get_contents('test.jpg');
$base64_str = base64_encode($file);
$len = strlen($base64_str);
$step = ceil($len/50000);

for ($i=0; $i <$step ; $i++) { 
    $substr = substr($base64_str, $i*50000,50000);
    $sql = "INSERT INTO b64_img VALUES( null,1,1,$i,&#39;$substr&#39;) ";
    $res = mysqli_query($link,$sql);
}

4. Generated data

5. Read database records and generate pictures [dm02_getImg.php]

/*链接数据库*/


$sql = "SELECT * FROM b64_img WHERE imgid = 1 ORDER BY bakid ASC ";
$res =    mysqli_query($link,$sql);
$data = array();
$imgStr = '';

while ($row = mysqli_fetch_assoc($res)) {
    $imgStr .= $row['bstr']    ;
}

$binaryStr = base64_decode($imgStr);
file_put_contents("ThisImg.jpg", $binaryStr);

6 , Successfully generated image

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